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Shale oil and gas are important strategic resources in China's energy sector, existing in shale formations with self-generation and self-storage characteristics. In 2012, a significant breakthrough was achieved in Fuling, China, with the discovery of marine shale gas, which led to the formulation of the "two-factor enrichment" theory. This theory proposes that the development of high-quality mud shale in deep-water continental shelves is fundamental for hydrocarbon generation and controlled storage, while favorable preservation conditions are key to reservoir formation and controlled production. Recent efficient exploration and development practices in shale oil and gas have indicated that China's continental shale oil also exhibits "two-factor enrichment" characteristics. By analyzing the characteristics of typical shale oil and gas reservoirs in China, this study incorporates shale oil and gas into a unified system of hydrocarbon formation, storage, and accumulation, further deepening the theoretical connotation of the "two-factor enrichment" theory and forming a new understanding of the uniformity in shale oil and gas enrichment. Future research trends are also explored. Results show that: (1) Sedimentary environments dominated by semi-deep to deep-water continental shelves and semi-deep to deep lakes are the basis for hydrocarbon generation and controlled storage, controlling both the abundance and type of organic matter in shales as well as the distribution of high-quality reservoirs and favorable lithofacies combinations. (2) Stable tectonic conditions, effective top and bottom seals, and self-sealing properties of shale, in conjunction with overpressure, provide good preservation conditions that are crucial for reservoir formation and controlled production, providing key guarantees for the enrichment and high production of shale oil and gas. (3) The formation and enrichment of shale oil and gas are part of a unified dynamic evolutionary system, with thermal evolution as the main driver, following the sequential formation of shale oil, condensate oil, and shale gas. (4) Future study should focus on strengthening the integrated evaluation of conventional and non-conventional resources, deepening the understanding of distribution coefficients for conventional and non-conventional oil and gas, and considering the distribution patterns of oil and gas from a holistic perspective. The research results have important scientific and practical significance for deepening the theory of shale oil and gas enrichment and guiding their exploration and development.

Based on the situation and progress of marine oil/gas exploration in the Sichuan Basin, SW China, the whole petroleum system is divided for marine carbonate rocks of the basin according to the combinations of hydrocarbon accumulation elements, especially the source rock. The hydrocarbon accumulation characteristics of each whole petroleum system are analyzed, the patterns of integrated conventional and unconventional hydrocarbon accumulation are summarized, and the favorable exploration targets are proposed. Under the control of multiple extensional-convergent tectonic cycles, the marine carbonate rocks of the Sichuan Basin contain three sets of regional source rocks and three sets of regional cap rocks, and can be divided into the Cambrian, Silurian and Permian whole petroleum systems. These whole petroleum systems present mainly independent hydrocarbon accumulation, containing natural gas of affinity individually. Locally, large fault zones run through multiple whole petroleum systems, forming a fault-controlled complex whole petroleum system. The hydrocarbon accumulation sequence of continental shelf facies shale gas accumulation, marginal platform facies-controlled gas reservoirs, and intra-platform fault- and facies-controlled gas reservoirs is common in the whole petroleum system, with a stereoscopic accumulation and orderly distribution pattern. High-quality source rock is fundamental to the formation of large gas fields, and natural gas in a whole petroleum system is generally enriched near and within the source rocks. The development and maintenance of large-scale reservoirs are essential for natural gas enrichment, multiple sources, oil and gas transformation, and dynamic adjustment are the characteristics of marine petroleum accumulation, and good preservation conditions are critical to natural gas accumulation. Large-scale marginal-platform reef-bank facies zones, deep shale gas, and large-scale lithological complexes related to source-connected faults are future marine hydrocarbon exploration targets in the Sichuan Basin.

Abstract Background Silage is widely used to formulate dairy cattle rations, and the utilization of antibiotics and methane emissions are 2 major problems for a sustainable and environmentally beneficial ruminant production systems. Bacteriocin has received considerable attention because of its potential as an alternative to antibiotics in animal husbandry. However, the impact of bacteriocin-producing lactic acid bacteria on the microbiological conversion process of whole-plant corn silage and rumen fermentation remains limited. The purpose of this study was to assess the effect of 2 class IIa bacteriocin-producing strains Lactiplantibacillus plantarum ATCC14917 and CICC24194 on bacterial community composition and ensiling profiles of whole-plant corn silage and its in vitro rumen fermentation, microbiota, and CH4 emissions. Results Both bacteriocin-producing strains increased the lactic acid concentration in silage fermented for 7 d, whereas the lowest lactic acid was observed in the ATCC14917 inoculated silage fermented for 90 d (P

Abstract Background Milk synthesis in lactating animals demands high energy metabolism, which results in an increased production of reactive oxygen metabolites (ROM) causing an imbalance between oxidants and antioxidants thereby inducing oxidative stress (OS) on the animals. To mitigate OS and postpartum disorders in dairy goats and gain insight into the impact of dietary choices on redox status during lactation, a feeding trial was conducted using alfalfa silage inoculated with a high-antioxidant strain of Lactiplantibacillus plantarum. Methods Twenty-four Guanzhong dairy goats (38.1 ± 1.20 kg) were randomly assigned to two dietary treatments: one containing silage inoculated with L. plantarum MTD/1 (RSMTD-1), and the other containing silage inoculated with high antioxidant activity L. plantarum 24-7 (ES24-7). Results ES24-7-inoculated silage exhibited better fermentation quality and antioxidant activity compared to RSMTD-1. The ES24-7 diet elevated the total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities in milk, serum, and feces of lactating goats (with the exception of T-AOC in milk). Additionally, the diet containing ES24-7 inoculated silage enhanced casein yield, milk free fatty acid (FFA) content, and vitamin A level in the goats’ milk. Furthermore, an increase of immunoglobulin (Ig)A, IgG, IgM, interleukin (IL)-4, and IL-10 concentrations were observed, coupled with a reduction in IL-1β, IL-2, IL-6, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α concentrations in the serum of lactating goats fed ES24-7. Higher concentrations of total volatile fatty acid (VFA), acetate, and propionate were observed in the rumen fluid of dairy goats fed ES24-7 inoculated silage. Moreover, the diet containing ES24-7 inoculated silage significantly upregulated the expression of nuclear factor erythroid 2 like 2 (NFE2L2), beta-carotene oxygenase 1 (BCO1), SOD1, SOD2, SOD3, GPX2, CAT, glutathione-disulfide reductase (GSR), and heme oxygenase 1 (HMOX1) genes in the mammary gland, while decreased the levels of NADPH oxidase 4 (NOX4), TNF, and interferon gamma (IFNG). Conclusions These findings indicated that feeding L. plantarum 24-7 inoculated alfalfa silage not only improved rumen fermentation and milk quality in lactating dairy goats but also boosted their immunity and antioxidant status by modulating the expression of several genes related to antioxidant and inflammation in the mammary gland.

Abstract This study investigates the effectiveness of an exopolysaccharide (EPS)‐producing strain (Lactiplantibacillus plantarum L75) alone or in combination with Saccharomyces cerevisiae on the fermentation characteristics, antioxidant capacities and microbial community successions of oat silage stored at various temperatures. A rapid decrease in pH and lactic acid accumulation was observed in silages treated with L. plantarum and S. cerevisiae (LS) as early as 3 days of ensiling (p

Deep shale gas is an important research direction for increasing shale gas storage and production in the Longmaxi Formation of Sichuan Basin. But there are differences in reservoir and seepage characteristics between shallow and medium-buried shale gas, which to some extent limits the progress of exploration and development of deep shale gas. In order to clarify the pore structure characteristics of deep shale gas reservoirs and the transport characteristics of shale free gas, this paper takes the high-quality shale of Longmaxi Formation in southern Sichuan as an example to carry out experiments on observing and quantitatively characterizing the pore structure of shale reservoirs. In addition, based on the transport mechanism of bulk gas, the transport characteristics, critical conditions, and dynamic evolution laws of shale free gas were explored. The experimental and computational results indicate that: (1) The pore morphology characteristics of deep shale reservoirs are not significantly different from those of shallow and medium-buried shale, but the pore structure characteristics of medium pores are more obvious, with pore volume accounting for 62.5%-69.7%; (2) The transport modes of deep shale free gas are divided into three types: transitional flow, slippage flow, and Darcy flow. The critical pore sizes of the three modes in the Yongchuan area are 4.2 nm and 420 nm, respectively. On this basis, a transport chart for free gas in the entire basin has been established; (3) From shallow to deep shale, the critical pore size corresponding to different transport modes of free gas decreases accordingly. The main transport mode of free gas changes from the transitional flow (up to 63.0%) to the slippage flow (up to 67.3%) and the Darcy flow accounts for no more than 2%. The transport capacity of free gas rapidly decreases from shallow to medium-buried shale, while the transport capacity of medium to deep shale free gas remains basically stable with increasing burial depth. By analyzing and comparing the pore structure characteristics and free gas transport characteristics of deep and shallow shale reservoirs, this study can effectively support the deployment of efficient exploration and development plans for deep shale gas and even shallow shale gas in the next step.

In order to accelerate the exploration and development of shale gas, this paper elaborates on the micro mechanism of shale gas preservation based on shale self-sealing. The self-sealing capacity of shale formations is mainly related to the low connectivity of nano-throats, low speed diffusion caused by bound water occurrence, capillary force sealing, and breakthrough pressure along the layer direction under burial conditions. Results of analysis based on shale pore morphology and connectivity show that the organic pores in shale are mainly composed of nano-throats with poor connectivity and significant retention effects. At the same time, the stacking of multiple relatively dense sealing layers within the top, bottom, and shale layers is conducive to self-sealing in longitudinal direction. Based on experimental and molecular dynamics simulation analysis of the influence of bound water on the diffusion and breakthrough pressure of the shale matrix, it is revealed that the bound water occurrence significantly reduces the effective diffusion capacity of shale matrix pores and could cause high capillary forces, leading to effective sealing of the gas stored in organic pores. In the study, the permeability-breakthrough pressure evolution relationship was constructed, revealing that under deep burial conditions, the effective closure of shale bedding fractures along the layer direction can form high breakthrough pressure sealing. During the uplift stage, under relatively weak tectonic compression, the shale could still maintain a high sealing capacity along the layer direction, which is conducive to shale gas preservation. However, under strong tectonic compression, the shale bedding fractures open and communicate with open fault surface, causing the failure of preservation capacity and large-scale loss of shale gas. This study elucidates the microscopic mechanism of shale gas preservation through experiments and molecular dynamics simulations, which could provide useful guidance for marine shale gas exploration in complex structural areas.

The gut microbiota is a diverse and complex population, and it has a key role in the host’s health and adaptability to the environment. The present study investigated the fecal bacterial community of wild grazing (WG) and domestic grazing (DG) yaks on natural grazing pastures, analyzing the gut microbiota using 16S rRNA sequencing to assess bacterial diversity. A total of 48 yak fecal samples were selected from two different grazing habitats. The DG group had more crude proteins and non-fiber carbohydrates. The WG group had more OM, insoluble dietary fiber such as NDF, ADF, ether extract, and TC. There were 165 and 142 unique operational taxonomic units (OTUs) in the WG and DG groups, respectively. Shannon index analysis revealed a higher bacterial diversity in the WG group than in the DG group. At the phylum level, Firmicutes were the dominant bacterial taxa in both groups. The relative abundance of Firmicutes in the WG group was higher than in the DG group. At the family level, the WG group had a significantly higher abundance of Ruminococcaceae (p < 0.001) and Rikenellaceae (p < 0.001) than the DG group. The abundances of Alloprevotella and Succinivibrio were more pronounced in the DG group than in the WG group at the genus level. This study presents a novel understanding of the bacterial communities of ruminants and their potential applications for livestock production.

Seven graded levels of sodium propionate (SP) diets with 0 (SP1), 0.2% (SP2), 0.4% (SP3), 0.6% (SP4), 0.8% (SP5), 1.0% (SP6), and 1.2% (SP7) were prepared to feed Trachinotus ovatus (initial body weight: 8.64 ± 0.08 g) for 56 days. The results showed that increasing dietary SP levels quadratically increased significantly final body weight (FBW), weight gain rate (WGR), and specific growth rate (SGR) of T. ovatus but linearly and quadratically decreased significantly viscerosomatic index (VSI) and hepatosomatic index (HSI) of T. ovatus (P

ABSTRACT This study investigated the microbial diversity, functionality, and fermentation quality of Elymus nutans (E. nutans) silage across different altitudinal gradients. Forage samples were gathered from three areas in Qinghai province, China, namely, Huangyuan (HY, altitude of 2,613 m); Xinghai (XH, altitude of 3,612 m), and Chenduo (CD, altitude of 4,589 m) counties. Chopped E. nutans were ensiled at local room temperature and sampled after 7, 14, 30, and 60 days of ensiling. The results exhibited that the bacterial diversity and numbers of the lactic acid bacteria (LAB) and yeast in E. nutans forage decreased, while the water-soluble carbohydrates and crude protein increased along the altitudinal gradients. This led to clear differences in fermentation qualities and bacterial community dynamics. The silage from CD with high altitude showed a higher fermentation quality, more stable bacterial network structure, and lower abundance of amino acid metabolism than ensiled forages collected from the other regions (P < 0.05). Meanwhile, the LAB including Lacticaseibacillus and Levilactobacillus were identified as differentially abundant taxa in silage sample from CD after 60 days of ensiling; in contrast, the undesirable microbiota were still the differentially abundant taxa in the silages from HY and XH. Correlation analysis further confirmed that altitude affects the epiphytic microbial structure and nutrition distribution of E. nutans forage, leading to varying levels of fermentation. Considering the complex microbial composition of fresh forage, LAB inoculation is highly suggested for E. nutans silage making in the Qinghai regions with low altitudes. IMPORTANCE On the Qinghai-Tibet Plateau (QTP), feed shortages are common due to cold environmental conditions and the short growing season of crops. Therefore, effective preservation, such as the ensiling of local forage, is becoming increasingly important to balance the seasonal imbalance between the forage supply and the nutritional needs of domestic animals in this area. However, the structure of the microbial community of the forage, which is influenced by climatic conditions such as altitude differences, has a major impact on the fermentation quality and microbial succession of the ensiled forage. Therefore, we investigated microbial community dynamics, co-occurrence, functional shifts, and natural fermentation profiles of Elymus nutans silage as a function of altitudinal gradients. Results show that silage from Chenduo at higher elevations has better fermentation quality and higher abundance of Lacticaseibacillus and Levilactobacillus than ensiled forage from other regions. This work may contribute to guiding for silage production in QTP.

Abstract Background Ferulic acid esterase (FAE)-secreting Lactiplantibacillus plantarum A1 (Lp A1) is a promising silage inoculant due to the FAE’s ability to alter the plant cell wall structure during ensiling, an action that is expected to improve forage digestibility. However, little is known regarding the impacts of Lp A1 on rumen microbiota. Our research assessed the influences of Lp A1 in comparison to a widely adopted commercial inoculant Lp MTD/1 on alfalfa’s ensilage, in vitro rumen incubation and microbiota. Results Samples of fresh and ensiled alfalfa treated with (either Lp A1 or Lp MTD/1) or without additives (as control; CON) and ensiled for 30, 60 and 90 d were used for fermentation quality, in vitro digestibility and batch culture study. Inoculants treated silage had lower (P

In September 2013, the National Energy Administration approved the establishment of Fuling national shale gas demonstration area (hereinafter referred to as the demonstration area), whose construction was completed in December 2015. After nearly one decade of development, it has grown into the main shale gas production base in China. In order to speed up the integration and breakthrough of China's shale gas theoretical understanding and exploration and development technology and effectively promote the great development of marine shale gas in China, this paper reviews and summarizes the development and construction history of the demonstration area, geological theory understanding, engineering technology and key equipment progress. And based on this, the future development direction of the demonstration area is predicted. And the following research results are obtained. First, shale gas exploration and development in the demonstration area is divided into three stages, i.e., exploration evaluation, phase I and II construction, and stacked development and adjustment. Second, the “binary enrichment” theory for marine shale gas and the engineering theory for efficiently developing gas reservoirs are innovatively established. Third, a series of supporting technologies are innovatively developed, such as optimized and fast drilling technology for shale gas cluster horizontal wells, differentiated network fracturing technology, high-efficiency gas production, gathering and transportation technology, and green development technology for karst mountains, and the localization of key equipment and tools is realized. Fourth, the efficient development of shallow overpressure shale gas reservoirs above 3500 m in depth and the effective development of shale gas reservoirs at the depth of 3500–4000 m are realized in the demonstration area. Fifth, the construction of the demonstration area in the future includes accelerating the development of normal-pressure deep shale gas, continuously tackling key shale gas EOR technologies, actively promoting the field application of new technologies and methods, and powerfully strengthening the construction of green demonstration areas. In conclusion, this demonstration area is the earliest one of four national shale gas demonstration areas, and its achievements will provide continuous guidance for the shale gas exploration and development in China and play a demonstrative and guiding role in promoting the development of shale gas geological theories and exploration and development technologies in China.

Abstract To explore the biofuel production potential of Caragana korshinskii Kom., Pediococcus acidilactici and an exogenous fibrolytic enzyme were employed to investigate the fermentation profile, structural carbohydrates degradation, enzymatic saccharification and the dynamics of bacterial community of C. korshinskii silage. After 60 d of ensiling, all additives increased the fermentation quality. The highest lactic and acetic acids and lowest non‐protein nitrogen (NPN) and ammonia nitrogen (NH3‐N) were observed in P. acidilactici and Acremonium cellulase (PA + AC) treated silage. Additionally, all additives significantly increased the ferulic acid content and fibre degradability with the highest values obtained from PA + AC silage. The bacterial community in all silages was dominated by P. acidilactici throughout the entire fermentation process. The bacterial community was also modified by the silage additives exhibiting a relatively simple network of bacterial interaction characterized by a lower bacterial diversity in P. acidilactici (PA) treated silage. The highest 6‐phospho‐beta‐glucosidase abundance was observed in PA‐treated silage at the mid‐later stage of ensiling. PA treatment exhibited lower structural carbohydrates degradation but performed better in lignocellulose conversion during enzymatic saccharification. These results indicated that pretreating C. korshinskii improved its silage quality and potential use as a lignocellulosic feedstock for the production of bio‐product and biofuel.

Abstract Lactic acid bacteria (LAB) play pivotal roles in the preservation and fermentation of forage crops in spontaneous or inoculated silages. Highlights of silage LAB over the past decades include the discovery of the roles of LAB in silage bacterial communities and metabolism and the exploration of functional properties. The present article reviews published literature on the effects of LAB on the succession, structure, and functions of silage microbial communities involved in fermentation. Furthermore, the utility of functional LAB in silage preparation including feruloyl esterase‐producing LAB, antimicrobial LAB, lactic acid bacteria with high antioxidant potential, pesticide‐degrading LAB, lactic acid bacteria producing 1,2‐propanediol, and low‐temperature‐tolerant LAB have been described. Compared with conventional LAB, functional LAB produce different effects; specifically, they positively affect animal performance, health, and product quality, among others. In addition, the metabolic profiles of ensiled forages show that plentiful probiotic metabolites with but not limited to antimicrobial, antioxidant, aromatic, and anti‐inflammatory properties are observed in silage. Collectively, the current knowledge on the roles of LAB in crop silage indicates there are great opportunities to develop silage not only as a fermented feed but also as a vehicle of delivery of probiotic substances for animal health and welfare in the future.

A feeding experiment was conducted to determine the effects of inoculating alfalfa silage with a ferulic acid esterase-producing inoculum on feed digestibility, rumen fermentation, antioxidant, and immunity status of lactating dairy goats. Twenty dairy goats were distributed into 2 experimental groups consisting of control diet (Lp MTD/1, including Lactobacillus plantarum MTD/1 inoculated silage) against diet containing silage treated with ferulic acid esterase-producing L. plantarum A1 (Lp A1). Alfalfa silage inoculated with a ferulic acid esterase-producing Lp A1 had better fermentation quality than the Lp MTD/1 inoculation. The application of Lp A1 improved silage antioxidant capacity as indicated by greater total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and glutathion peroxidase (GSH-Px) activities in Lp A1 treated silage versus Lp MTD/1 treatment. Compared with Lp MTD/1 treated group, inoculation of silage with Lp A1 increased apparent total tract digestibility of dietary dry matter, organic matter and crude protein, and ruminal concentrations of total volatile fatty acids, acetate, propionate and isobutyrate as well. The results of current study also demonstrated improved antioxidant capacity and immune performance of dairy goats with Lp A1 inoculation. Feeding Lp A1-treated silage increased dairy goats' serum antioxidase activity, such as T-AOC, SOD, GSH-Px and catalase, and the serum concentration of immunoglobulin A, while decreased tumor necrosis factor α, interleukin (IL)-2 and IL-6. In addition, compared with Lp MTD/1, diet containing alfalfa silage inoculated with Lp A1 endowed dairy goats' milk with greater fat and protein contents, improved dairy goat milk quality without affecting feed efficiency.

The experiment was conducted to investigate the effects of dietary leucine on growth, antioxidant capacity, immune response, and inflammation in juvenile yellow catfish. Five diets were formulated to contain five dietary leucine levels: 12.00 (control), 19.00, 26.00, 33.00, and 40.00 g kg−1. Each diet was randomly assigned to triplicate groups of 30 juvenile fish (5.02 ± 0.15 g) twice daily to apparent satiation for 56 days. Weight gain rate, specific growth rate, and activities of liver superoxide dismutase, glutathione peroxidase, and serum lysozyme, as well as immunoglobulin M content, significantly increased with increase in dietary leucine levels up to 26.00 g kg−1, but those values decreased significantly with a further increase in dietary leucine. On the contrary, the lowest malondialdehyde content was found in 26.00 and 33.00 g kg−1 leucine groups. The expression levels of IGF 1 and MYF 5 genes in muscle were significantly upregulated with increase in dietary leucine levels up to 26.00 g kg−1, but the expression of MSTN level showed the opposite trend. The lowest expression levels of IL 8 and TNFɑ genes in the liver were found in 26.00 g kg−1 leucine groups. The quadratic regression analysis on weight gain, specific growth rate, and feed conversion ratio against dietary leucine levels indicated that the optimal dietary leucine requirement was estimated to be 26.84–27.00 g kg−1of the dry diet.

Accelerating the development of renewable energy and reducing CO2 emissions have become a general consensus and concerted action of all countries in the world. The electric power industry, especially thermal power industry, is the main source for fossil energy consumption and CO2 emissions. Since solvent-based post-combustion carbon capture technology would bring massive extra energy consumption, the application of solar-assisted carbon capture technology has attracted extensive attention. Due to the important role of coal-fired combined heat and power plants for serving residential and industrial heating districts, in this paper, the low-carbon operation benefits of combined heat and power integrated plants based on solar-assisted carbon capture (CHPIP-SACC) are fully evaluated in heat and power integrated energy system with a high proportion of wind power. Based on the selected integration scheme, a linear operation model of CHPIP-SACC is developed considering energy flow characteristics and thermal coupling interaction of its internal modules. From the perspective of system-level operation optimization, the day-ahead economic dispatch problem based on a mix-integer linear programming model is presented to evaluate the low-carbon benefits of CHPIP-SACC during annual operation simulation. The numerical simulations on a modified IEEE 39-bus system demonstrate the effectiveness of CHPIP-SACC for reducing CO2 emissions as well as increasing the downward flexibility. The impact of different solar field areas and unit prices of coal on the low-carbon operation benefits of CHPIP-SACC is studied in the section of sensitivity analysis.

Abstract Background Bacillus amyloliquefaciens (BA) and Bacillus subtilis (BS) are usually used as feed supplements directly or bacterial inoculants in biological feeds for animals. However, few research have reported the effects of BA and BS on fermentation characteristics and bacterial community successions of whole-plant corn silage during ensiling. If the BA and BS inoculants have positive effects on silages, then they could not only improve fermentation characteristics, but also deliver BA or BS viable cells to ruminants, which would play its probiotic effect. Therefore, the objectives of this study were to investigate the effects of BA and BS on the fermentation, chemical characteristics, bacterial community and their metabolic pathway of whole-plant corn silage. Results Freshly chopped whole-plant corn was inoculated without or with BA and BS, respectively, and ensiled for 1, 3, 7, 14 and 60 d. Results showed that BA and BS inoculations increased lactic acid concentrations of whole-plant corn silages compared with control, and BA inoculation decreased acetic acid concentrations, whereas BS inoculation decreased fiber contents and increased crude protein (CP) content. Higher water-soluble carbohydrate contents and lower starch contents were observed in BA- and BS-inoculated silages compared with that in control. The decreased CP content and increased non-protein nitrogen content were observed in BA-inoculated silage, which was consistent with the higher amino acid metabolism abundances observed in BA-inoculated silage. In addition, it was noteworthy that BA and BS inoculations increased the metabolism of cofactors and vitamins, and decreased the relative abundances of drug resistance: antimicrobial pathways. We also found that the bacterial metabolism pathways were clearly separated into three clusters based on the ensiling times of whole-plant corn silage in the present study. There were no significant differences in bacterial community compositions among the three groups during ensiling. However, BA and BS inoculations decreased the relative abundances of undesirable bacteria such as Acetobacter and Acinetobacter. Conclusion Our findings suggested that the BS strain was more suitable as silage inoculants than the BA strain in whole-plant corn silage in this study.

Cladophora members are present in seawater and freshwater ecosystems worldwide. Their growth poses a serious threat to water environment, fisheries, production and living. In order to explore safe and ecological treatment methods, the inhibitory effects and oxidative damages (48 and 96 h) in Cladophora sp. (Cladophoraceae) exposed to 0–0.30 g L−1 berberine were investigated. Results showed that the LC 50 of berberine to Cladophora was 0.147 g L−1 and 0.063 g L−1 at 48 h and 96 h, respectively. Malondialdehyde and total protein contents first increased and then decreased sharply with increasing exposure concentrations of berberine. The Cladophora cells accelerated protein synthesis when their cell membranes were subjected to oxidative damage. Superoxide dismutase activity was down-regulated slightly after exposure to low berberine concentration (0.05 g L−1) and strongly when the Cladophora cells suffered from great oxidative damage. Total antioxidant capacity (T-AOC) first decreased sharply and then increased with increasing exposure concentrations of berberine. The decrease in T-AOC indicated the enzymatic antioxidants were continuously inhibited with increasing exposure concentrations of berberine. The increase in T-AOC indicated the secretion of non-enzymatic antioxidants was continuously strengthened with increasing exposure concentrations of berberine. Cladophora DNA also underwent oxidative damage due to berberine. Low concentrations of berberine activated its repair mechanisms, but high concentrations could cause irreparable damage. Therefore, these results suggested that berberine could inhibit the growth of Cladophora by oxidative damage, and Cladophora responded physiologically to this stress accordingly.

Taking key wells such as Yuanye 3 in the Yuanba area of the Sichuan Basin as examples, the accumulation conditions of continental shale oil and gas in the Middle Jurassic Qianfoya Formation in this area have been evaluated based on core observation and experimental analysis. The organic-rich mudstone of the Qianfoya Formation has high porosity and good oil and gas content. It is the main reservoir lithofacies type, while the physical properties of limestone and sandstone interlayers are relatively poorer. The pores are mainly inorganic ones, accounting for approximately 60% to 80% of the total porosity. Compared with marine shale, the proportion of micropores is lower and the content of macropores is higher, which is conducive to the production of shale oil and gas. The fourth section of the lower part of the second member of the Qianfoya Formation is dominated by organic-rich mudstone, with a high shale-to-stratum ratio, an average porosity of 5.43%, and an average total organic carbon (TOC) content of 1.72%. The free hydrocarbon content (S1) of frozen sample pyrolysis is 2.63 mg/g, and the average total gas content is 1.51 m3/t, showing a good oil-bearing property and favorable geological conditions for the formation of continental shale oil and gas. Comparative analysis with other wells has indicated that half-deep lacustrine facies is the most favorable sedimentary facies belt, providing basic material for oil and gas enrichment, and high maturity and fracture development is the important condition for oil and gas enrichment.

Since the concept, DNA damage repair has been stated as a natural biological event, and research has increasingly revealed its strong association to tumors, aging, immunity, biochemical detection, and other factors. The discovery of abnormal DNA repair in cancers has been heralded as a paradigm shift in the treatment of malignancies. A poly (ADP-ribose) polymerase (PARP) activates poly (ADP-ribosylation) to repair single-strand DNA breaks after DNA damage. In some cancers, such as breast cancer and gastric cancer, a PARP inhibitor can target the DNA damage response pathway, prevent DNA repair, and induce homologous recombination deficiency (HRD) tumors to create the phenomena of synthetic lethality. Increasingly, clinical trials are being submitted to research the uses of PARP inhibitors in various types of cancers. Small cell lung cancer (SCLC) is a quickly growing malignancy with numerous therapeutic limitations and a dismal prognosis. Sequencing of mutant genes revealed multiple gene connections that may contribute to its carcinogenesis, indicating a viable study direction. Furthermore, the therapy of SCLC with PARP inhibitors has been further explored. The mechanism of PARP action, as well as the advancement of its preclinical and clinical applications in SCLC, will be discussed in this review.

Summary The objectives of this study were to investigate the adaptation and competition of Lactobacillus plantarum, Pediococcus pentosaceus and Enterococcus faecalis inoculated in alfalfa silage alone or in combination on the fermentation quality, dynamics of bacterial community, and their functional shifts using single‐molecule real‐time (SMRT) sequencing technology. Before ensiling, alfalfa was inoculated with L. plantarum (Lp), P. pentosaceus (Pp), E. faecalis (Ef) or their combinations (LpPp, LpEf, LpPpEf) and sampled at 1, 3, 7, 14 and 60 days. After 60‐days fermentation, the Lp‐, Pp‐ and LpPp‐inoculated silages had lower pH but greater concentrations of lactic acid were observed in Pp, LpEf and LpPpEf‐inoculated silages. The inoculants altered the keystone taxa and the bacterial community dynamics in different manners, where L. plantarum, Weissella cibaria and L. pentosaceus dominated the bacterial communities after 14 days‐fermentation in all treatments. The silages with better fermentation quality had simplified bacterial correlation structures. Moreover, different inoculants dramatically changed the carbohydrate, amino acid, energy, nucleotide and vitamin metabolism of bacterial communities during ensiling. Results of the current study indicate that effect of different inoculants on alfalfa silage fermentation was implemented by modulating the succession of bacterial community, their interactions and metabolic pathways as well during ensiling.

Summary Multi‐omics approach was adopted to investigate the modulation of bacterial microbiota and metabolome as well as their interactions in whole crop corn ensiling systems by inoculating homofermentative Lactobacillus plantarum or heterofermentative Lactobacillus buchneri. Inoculations of the two different inoculants resulted in substantial differences in microbial community and metabolic composition as well as their dynamics in ensiled corn. Inoculants also altered the correlations of microbiota in different manners, and various keystone species were identified in corn silages with different treatments. Many metabolites with biofunctional activities like bacteriostatic, antioxidant, central nervous system inhibitory and anti‐inflammatory were found in the present silage. A constitutive difference in microbiota dynamics was found for several pathways, which were upregulated by specific taxa in middle stage of fermentation, and widespread associations between metabolites with biofunctions and the species of lactic acid bacteria dominated in silage were observed. Multiple microbial and metabolic structures and dynamics were correlated and affected the fermentation process of the corn ensiling systems. Results of the current study improve our understanding of the complicated biological process underlying silage fermentation and provide a framework to re‐evaluate silages with biofunctions, which may contribute to target‐based regulation methods to produce functional silage for animal production.

ABSTRACT The objective of this study was to investigate effects of different lactic acid bacteria (LAB) on the fermentation process of whole-plant corn silage stored at different temperatures based on bacterial community successions, interaction networks, and predicted functions. Before ensiling, whole-plant corn was inoculated with L. plantarum (LP) or L. buchneri (LB) and the silage bags were stored at 20 or 30°C, and sampled after 0.5, 1, 3, 7, 14, and 60 d of ensiling. The higher abundances of Leuconostoc, Pedicoccus and Weissella were observed in silage stored at 30°C after 12 h of ensiling, thereby rapidly decreased pH to about 4.5. According to meta-network analysis, the bacterial communities were more sensitive to storage temperature than LAB inoculants during whole-plant corn ensiling. Species of Lactobacillus and Weissella were sensitive to 30°C, while Leuconostoc species were sensitive to 20°C in whole-plant corn silage. The storage temperature of 30°C decreased bacterial diversity and network complexity of whole-plant corn silage compared with 20°C. Additionally, LP inoculation changed the bacterial community successions during the early and middle ensiling periods, while LB inoculation affected bacterial community successions in the later stage of ensiling. The metabolic pathways of bacterial community were totally different in LB-inoculated silage from that in control and LP-inoculated silage. As the bacterial compositions became simple along with the ensiling process, the functional structure of bacterial community became simplified as well. In general, the storage temperature had a greater impact on the fermentation characteristics, bacterial community and predicted function of whole-plant corn silage compared with LAB inoculations. IMPORTANCE Increased understanding of effects of regulation measures on whole-plant corn silage is important from bacterial community succession, interaction network and predicted functions. According to alpha diversity and meta co-occurrence network, the bacterial communities were more sensitive to storage temperature than LAB inoculants during whole-plant corn ensiling. The storage temperature of 30°C decreased bacterial diversity and network complexity of whole-plant corn silage compared with 20°C. In addition, 30°C promoted the initiation of LP and LB inoculants, and 20°C was conducive to the long-term growth of LP and LB inoculants. According to the changes of bacterial community and predicated functions, it was further confirmed that the effect of LB inoculation was more obvious on whole-plant corn silage.

In recent years, major breakthroughs have been made in natural gas exploration in deep and ultra-deep strata in the Sichuan Basin, but the overall successful rate is low. To further clarify the prospects there, it is necessary to make an in-depth analysis of the previously discovered large-scale reef-shoal gas fields such as Puguang, Yuanba, Anyue and Longgang and deep shale gas discovery in Dingshan and Dongxi, southern Sichuan Basin. On one hand, large high-energy facies are the basis for controlling the development of large-scale reef-shoal reservoirs in conventional reef-shoal areas. The reservoir original porosity is high. The atmospheric freshwater dissolution in the early diagenetic stage, dolomitization, unconformity karst, and “pore–fracture coupling” mainly control the development of secondary pores. The contribution of hydrothermal fluids to reservoir is double-sided, and such early pores can be preserved till present due to those retention processes such as early hydrocarbon charging. Apart from continuous preservation as the key factor, most gas reservoirs are featured by “near-source enrichment, phase transformation, and dynamic adjustment”. On the other hand, deep shale gas generally has the characteristics of “high pressure, high porosity, and high gas content”, that is, “overpressure and rich gas”. The key to the development of high-quality deep shales with high pores are “quartz compression retaining pore'' and “reservoir fluid overpressure”. The weak tectonic effect in the late stage is the main reason for deep shale gas to maintain the “high pressure and high gas content”. In conclusion, technological advances like geological target identification and “sweet spot” prediction, as well as deep, high-temperature and high-pressure engineering processes, are the guarantee for efficient exploration of conventional and unconventional deep and ultra-deep natural gas, which has great potential in the Sichuan Basin.

Marine strata in South China are mainly distributed in the Paleozoic and Mesozoic. The strata are old and the thermal evolution degree is high. It was controlled by the multi-cycle sedimentary and multi-stage structural evolution history. The petroleum basic geological conditions are superior, but the distribution of oil and gas is complicated. Oil and gas exploration has mainly gone through three stages: general survey, structural reservoir, massive lithologic gas reservoir and shale gas exploration. Although major breakthroughs have been made in many fields, the overall detection rate is low. A systematic summary of the early discovery of large gas fields and the new progress of exploration was made in order to clarify the prospects for oil and gas exploration. There is a large potential for marine petroleum exploration in South China. Deep and ultra-deep strata as well as new areas are important breakthrough directions in the Sichuan Basin. The unconventional shale gas reservoirs in the Upper Ordovician Wufeng-Lower Silurian Longmaxi formations and the conventional gas reservoirs in the platform margin zone of the Upper Sinian Dengying Formation in Langzhong-Yuanba, the platform inner beach facies in the Sinian-Cambrian in Tongnanba, the pre-salt strata in the lower assemblage in Qijiang in the southern Sichuan and the reef beach facies in the Permian-Triassic have a total resource amount to trillions of cubic meters, which is expected to achieve a new round of breakthroughs and discoveries. Besides, unconventional shale gas in the Permian and Jurassic and some new targets for conventional gas such as hydrothermal dolomites, karst fissure group, stucco limestones and sedimentary tuffs in the Permian show a great exploration potential. New discoveries continue to be made in complex basin-margin regions in the Sichuan Basin. Shale gas in the residual syncline area and conventional piedmont areas in the basin margin are the main exploration directions. The periphery of ancient uplifts and the progressive deformation area in the southern periphery have weak structural deformation, and the preservation conditions are favorable with a certain exploration potential, and are expected to become a strategic succession area for oil and gas.

As the hydrocarbon generation and storage mechanisms of high quality shales of Upper Ordovician Wufeng Formation- Lower Silurian Longmaxi Formation remain unclear, based on geological conditions and experimental modelling of shale gas formation, the shale gas generation and accumulation mechanisms as well as their coupling relationships of deep-water shelf shales in Wufeng–Longmaxi Formation of Sichuan Basin were analyzed from petrology, mineralogy, and geochemistry. The high quality shales of Wufeng–Longmaxi Formation in Sichuan Basin are characterized by high thermal evolution, high hydrocarbon generation intensity, good material base, and good roof and floor conditions; the high quality deep-water shelf shale not only has high biogenic silicon content and organic carbon content, but also high porosity coupling. It is concluded that: (1) The shales had good preservation conditions and high retainment of crude oil in the early times, and the shale gas was mainly from cracking of crude oil. (2) The biogenic silicon (opal A) turned into crystal quartz in early times of burial diagenesis, lots of micro-size intergranular pores were produced in the same time; moreover, the biogenic silicon frame had high resistance to compaction, thus it provided the conditions not only for oil charge in the early stage, but also for formation and preservation of nanometer cellular-like pores, and was the key factor enabling the preservation of organic pores. (3) The high quality shale of Wufeng–Longmaxi Formation had high brittleness, strong homogeneity, siliceous intergranular micro-pores and nanometer organic pores, which were conducive to the formation of complicated fissure network connecting the siliceous intergranular nano-pores, and thus high and stable production of shale gas. Key words: hydrocarbon generation and storage mechanism, Upper Ordovician Wufeng Formation, Lower Silurian Longmaxi Formation, deep-water shelf, siliceous shale, Sichuan Basin, pore preservation

The objective of this study was to investigate the effects of inoculating two bacteriocin-producing strains, Lactiplantibacillus plantarum ATCC14917 and LP1-4, at ensiling on the in vitro ruminal fermentation characteristics and methane production of alfalfa silage with two dry matter (DM)contents. Before ensiling, fresh alfalfa was wilted to a moderate DM content (355 g/kg) and a high DM content (428 g/kg). The wilted alfalfa was treated with (1) distilled water (control), (2) commercial strain L. plantarum MTD/1 (MTD/1), (3) bacteriocin-producing L. plantarum ATCC14917 (ATCC14917), and (4) a bacteriocin-like substance producing L. plantarum LP1-4 (LP1-4) at 1 × 105 colony forming units (CFU)/g fresh weight. After 90 d of ensiling, the silages were used for in vitro rumen fermentation. Inoculation with the two bacteriocin-producing strains at ensiling remarkably reduced (p < 0.05) in vitro ruminal CH4 production and enhanced DM digestibility compared with the control group regardless of DM content. For silages with high DM content, inoculation with the bacteriocin-producing strains even increased (p < 0.05) in vitro ruminal total volatile fatty acid production. Therefore, the bacteriocin-producing inoculants have a great potential to mitigate ruminal methane emission but without an adverse effect on rumen fermentation of the inoculated alfalfa silage.

This study investigated the effects of two bacteriocin-producing Lactiplantibacillus plantarum strains on fermentation, bacterial communities, and their functions of alfalfa silage with two dry matter (DM) contents of 355 (moderate DM) and 428 (high DM) g/kg fresh weight. Before ensiling, alfalfa was treated with (1) distilled water (control), (2) the commercial strain L. plantarum MTD/1, (3) bacteriocin-producing L. plantarum ATCC14917, and (4) bacteriocin-producing L. plantarum LP1-4, and ensiled for 3 d, 7 d, 14 d, 60 d, and 90 d, respectively. Application of ATCC14917 promoted lactic acid production in the moderate DM silage at the early fermentation stage (3 d). Silages treated with ATCC14917 and LP1-4 showed lower DM losses and non-protein nitrogen concentrations versus the control or MDT/1-treated silage (p < 0.05). During fermentation, a high proportion of Weissella cibaria was observed in the silages with high DM content from 3 to 60 d of ensiling, and the functions of carbohydrate and amino acid metabolisms of silage bacterial community were decreased by ATCC14917 before 60 d of ensiling. In addition, ATCC14917 also inhibited the growth of Aerococcus and Enterobacter in silage. Therefore, the bacteriocin-producing L. plantarum ATCC14917 has a great potential to improve alfalfa silage quality, nutritive value, and safety as well.

Marine–continent transitional facies shale of the Longtan Fm, Upper Permian is an important source rock stratum in the Sichuan Basin. The previous researches on it mainly focus more on source rock evaluation, but less on shale gas accumulation. In this paper, the test and analysis results of Well DYS1, the coring well of Longtan Fm were dissected. Combined with the drilling results of its adjacent area, the organic rich shale in the Longtan Fm were studied from the aspects of distribution, geochemical, reservoir, gas-bearing characteristics and roof and floor conditions, and then compared with the shale strata with similar sedimentary background and good shale gas shows. And accordingly, its geological conditions for the formation of Longtan shale gas and its exploration potential were made clear. And the following research results were obtained. First, in the southeastern Sichuan Basin, the organic rich shale of transitional facies of Longtan Fm is developed with a thickness of more than 40 m. It is characterized by high brittle mineral content, high porosity, high total organic carbon (TOC), moderate thermal evolution (Ro) and good gas-bearing property. Therefore, it is geologically favorable for the formation of shale gas. Second, compared with the existing transitional facies shales at home and abroad, the Longtan shale is better in terms of porosity, TOC, Ro, gas content and other key parameters. Third, the type of organic matters is the main reason for the low development degree of organic pores in the Longtan shale. And during its shale gas exploration and selection, the coal seam enriched sections shall be avoided. In conclusion, considering the development degree, interlayer thickness, depth and preservation conditions of organic rich shale comprehensively, the Qijiang–Chishui area is the best exploration area for the transitional facies shale gas of Longtan Fm in the Sichuan Basin. Keywords: Sichuan basin, Late Permian, Longtan Fm, Marine–continental transitional facies, Shale, Total organic carbon, Thermal evolution maturity, Gas content, Shale gas exploration potential

Oil/gas exploration around the world has extended into deep and ultra-deep strata because it is increasingly difficult to find new large-scale oil/gas reservoirs in shallow–middle buried strata. In recent years, China has made remarkable achievements in oil/gas exploration in ultra-deep areas including carbonate and clastic reservoirs. Some (ultra) large-scale oil and gas fields have been discovered. The oil/gas accumulation mechanisms and key technologies of oil/gas reservoir exploration and development are summarized in this study in order to share China’s experiences. Ultra-deep oil/gas originates from numerous sources of hydrocarbons and multiphase charging. Liquid hydrocarbons can form in ultra-deep layers due to low geothermal gradients or overpressures, and the natural gas composition in ultra-deep areas is complicated by the reactions between deep hydrocarbons, water, and rock or by the addition of mantle- or crust-sourced gases. These oils/gases are mainly stored in the original high-energy reef/shoal complexes or in sand body sediments. They usually have high original porosity. Secondary pores are often developed by dissolution, dolomitization, and fracturing in the late stage. The early pores have been preserved by retentive diageneses such as the early charging of hydrocarbons. Oil/gas accumulation in ultra-deep areas generally has the characteristics of near-source accumulation and sustained preservation. The effective exploration and development of ultra-deep oil/gas reservoirs depend on the support of key technologies. Use of the latest technologies such as seismic signal acquisition and processing, low porosity and permeability zone prediction, and gas–water identification has enabled the discovery of ultra-deep oil/gas resources. In addition, advanced technologies for drilling, completion, and oil/gas testing have ensured the effective development of these fields. Keywords: Oil/gas exploration, Ultra-deep, Oil/gas sources, Reservoir, Petroleum accumulation, Exploration and exploitation technologies

Pingqiao Shale Gas Field in Fuling Area of Sichuan Basin in China is located in a narrow-abrupt fault anticline of the Fenglai Syncline. Presently, the proven geological reserves of shale gas are 138.917 × 109 m3 in the Pingqiao Shale Gas Field, suggesting good potential for shale gas exploration in the Pingqiao Shale Gas Field. According to the drilling, logging, as well as the seismic and experimental data, the basic features of the Pingqiao Shale Gas Field with the narrow-abrupt fault anticline structure is outlined. Herein, the major factors controlling the accumulation and the high productivity, as well as the reasons for the differences in the production in the Pingqiao Shale Gas Field are also analyzed. The studies show the following: (1) The thickness of the shale gas layers (TOC ≥ 1%) is 115–155 m, the thickness of quality shale layers (TOC ≥ 3%) at the bottom of Wufeng-Longmaxi Formation in the Pingqiao Shale Gas Field is 36–40 m, which is featured by the high abundance in reserves (1.268 × 109 m3/km2), high pressure of shale gas accumulation (pressure ratio 1.56) and the high production value (average testing production 219.9 × 103 m3/d). (2) Main factors controlling shale gas accumulation and production in the Pingqiao Shale Gas Field include developed quality shales in the deep shelf, no faults stretching to the surface, weak slipping, good sealing, no outcrops and no obvious pressure-released belts in the surrounding area. (3) The development degree of the micro-fractures, structure position and depth are the key factors for the differences in production when shale gas layers have similar enrichment conditions. Keywords: Pingqiao Shale Gas Field, Wufeng-Longmaxi Formation, Narrow-abrupt faulted anticline, Preserving conditions, Main factors controlling shale gas accumulations

Silage is widely used as ruminant feed all over the world. Lactic acid bacteria inoculants are commonly applied in silage production to improve preservation efficiency. To investigate the effects of lactic acid bacteria-inoculated silage on the bacterial communities and metabolites of the digestive tract, twenty-four local hybrid rams (a hybrid of Small Tail Han sheep and Mongolian sheep with an average initial BW 27.8 ± 3.05 kg) were randomly divided into four groups fed with corn stalk (S), corn stalk silage, corn stalk silage treated with Lentilactobacillusplantarum (P), or corn stalk silage treated with L. buchneri (B). The results showed that compared with the control and B groups, the inoculant with P significantly increased silage dry matter (DM) content, while the pH value was significantly higher than that in group B, and the aerobic stability was significantly lower than that in group B. Firmicutes and Bacteroidetes were the two dominant phyla of digestive tract microbiota in sheep. Compared with corn stalk, sheep fed with corn stalk silage showed a higher relative abundance of Prevotella. P-treated silage decreased the relative abundance of Firmicutes at the phylum level in rumen fluid. Silage treated with P or B increased the relative abundance of Prevotella, Ruminococcus, and Fibrobacter at the genus level in the rumen. A total of 498 differential metabolites in the rumen were detected when comparing the corn stalk and corn stalk silage groups. A total of 257 and 141 differential metabolites were detected when comparing the untreated silage and silages treated with P and B, respectively. These metabolites in the sheep rumen were correlated with bacterial communities, especially Butyrivibrio, Fibrobacter, and Prevotella. In conclusion, the addition of P and B during ensiling could change the fermentation and metabolites in the rumen by influencing the bacterial community. The change induced by these inoculants might be beneficial for animals’ performance and the health of ruminants.

Feed deficiency during the long cold period of a year is one of the major problems that the traditional year-round animal grazing system has faced on the Qinghai-Tibetan plateau (QTP) since ancient time. Therefore, ensiling the grasses from grassland could be a desirable feeding regime to preserve high quality forage and to alleviate the seasonal unbalanced feed supply problem on this plateau. The present study was designed to investigate dynamics of bacterial community and natural fermentation quality of ensiled Elymus nutans collected from grasslands in four different areas with different elevations [Tianzhu County (TZ), 2965 m; Golog Prefecture (GL), 3763 m; Damxung County (DX), 4228 m, and Nagqu Prefecture (NQ), 4752 m] on the QTP. The bacterial community was characterized by using the PacBio single molecule with real-time sequencing technology (SMRT). The harvested fresh E. nutans grasses were ensiled in vacuum-sealed polyethylene bags for 14, 30, 60, and 90 days. Obvious differences in the epiphytic bacterial community of the fresh E. nutans samples from the four areas were observed, which resulted in various bacterial community dynamics and fermentation qualities of ensiled E. nutans. Higher fermentation quality was observed in silage samples from Nagqu than in those from the other areas (P < 0.05). Lactic acid bacteria (LAB) involved in fermentation of E. nutans from low altitude areas consisted of Pediococcus pentosaceus, Lactobacillus sp., Leuconostoc mesenteroides, and Lactobacillus coryniformis, whereas major LAB species involved in the fermentation of E. nutans silage from high altitudes included L. mesenteroides, Lactobacillus brevis, and Lactobacillus sp. Correlation analysis between bacterial composition and fermentation quality of E. nutans silages made from the four different areas in the QTP indicated that the LAB species responsible for silage fermentation in different areas were totally different, which was mainly due to the different epiphytic bacterial compositions in fresh E. nutans before ensiling. The present results provide important information on revealing the bacterial communities and fermentation quality of ensiled E. nutans, and on future screening of LAB isolates for making high quality silage in order to alleviate feed shortage of the traditional year-round grazing system on the QTP.

Availability of feedstock is one of the uncertainties impeding cellulosic biofuel production, and conservation of whole crop biomass as silage is a promising method to ensure year-round feedstock availability for biofuel production. This study investigated lignocellulose degradation and subsequent enzymatic hydrolysis of a 90-d sorghum silage incorporated with soybean and inoculated with Lactobacillus plantarum A1 in a three (0, 25, and 50%; soybean inclusions) by two (uninoculated and inoculated) factorial experiment. The results revealed that L. plantarum A1 inoculated silages had improved fermentation characteristics. The silages’ total N and non-fiber carbohydrate increased with L. plantarum A1 and soybean inclusion (p < 0.05). Inoculation also increased the residual water-soluble carbohydrate by 33.9% (p < 0.05). Inoculation and soybean inclusion significantly hydrolyzed the biomass’ lignocellulose, altered its morphology and microstructural matrix, increased production of ferulic acid and reduced the biomass crystallinity by 15.60% (p < 0.05). L. plantarum A1 inoculation × soybean inclusion improved glucose yield and cellulose conversion during enzymatic saccharification compared to uninoculated treatments. Therefore, incorporating soybean into sorghum silage with L. plantarum A1 inoculation enhanced fermentation quality, lignocellulose degradation and enzymatic saccharification which could serve as a sure way for sustainable year-round feedstock supply for enhanced biofuel production.

To solve the difficulties in exploration and development in Yuanba ultra-deep gas field in Sichuan Basin, SW China, the article studies the mechanism of quality reef reservoirs development and gas accumulation and innovates techniques in ultra-deep seismic exploration, drilling, completion and testing. Through the reconstruction of dynamic depositional evolution process and regional depositional framework of homoclinal ramp-rimmed platform in Upper Permian, three theories are put forward: first, “early beach-late reef, multiple stacking, arrangement in rows and belts” is the sedimentary mode for the reservoirs in the Changxing Formation of Yuanba area; second, “dissolution in early exposure stage and dolomitization during shallow burial giving rise to the pores in matrix, overpressure caused by cracking of liquid hydrocarbon during deep burial inducing fractures” is the reservoirs development mechanisms; third, “coupling of pores and fractures” controls the development of high quality reservoirs in deep formations. From correlation of oil and source rock, it is concluded that the Wujiaping Formation and Dalong Formation of deep-water continental shelf are the major source rocks in the Permian of northern Sichuan Basin. The hydrocarbon accumulation mode in ultra-deep formations of low-deformation zones is characterized by “three-micro (micro-fault, micro-fracture interbed crack) migration, near-source enrichment, and persistent preservation”. Through seismic inversion using the pore structure parameters of pore-fracture diadactic structure model, the high production gas enrichment area in Yuanba gas field is 98.5 km2. Moreover, special well structure and unconventional well structure were used to deal with multiple pressure systems and sealing of complex formations. A kind of integral, high pressure resistant FF-level gas wellhead and ground safety linkage device was developed to accomplish safe and environmentally friendly gas production. Key words: Sichuan Basin, Yuanba gas field, ultra-deep formation, Changxing Formation, reef, seismic exploration, testing technology

In order to explore whether beneficial lactic acid bacteria (LAB) could prolong the shelf life and improve the quality of fresh-cut apples, Lactiplantibacillus plantarum BX62, which was isolated from traditional fermented yak yogurt, and chitosan (CT), were applied to fresh-cut apples, subsequently stored at 4 °C. On days 0, 2, 4, 6, and 8, apple slices were taken for physicochemical, microbiological analysis, and sensory evaluation. The results showed that apple slices coated with L. plantarum BX62 (8 log CFU/mL) presented lower weight loss and browning rate, higher DPPH scavenging capacity, and achieved more effective inhibition of polyphenol oxidase (PPO) and peroxidase (POD) activities compared to the control samples. The application of CT alone or in combination with L. plantarum BX62 resulted in a significant reduction in aerobic mesophilic bacteria (AMB), aerobic psychrophilic bacterial (APB), yeast and molds (YAMs) counts (2.31 log CFU/g for AMB, 2.55 for APB, and 1.58 for YAMs). In addition, L. plantarum BX62 coated apples showed acceptable sensory properties in terms of color, flavor, taste, texture, and overall visual quality during 8 d of storage. On this basis, L. plantarum BX62 could be used as an excellent bio-preservative to extend the shelf life and improve the quality of fresh-cut apples.

With the implementation of modern scientific protocols, the average human lifespan has significantly improved, but age-related problems remain a challenge. With the advent of ageing, there are alterations in gut microbiota and gut barrier functions, weak immune responses, increased oxidative stress, and other age-related disorders. This review has highlighted and discussed the current understanding on the significance of gut microbiota dysbiosis and ageing and its inherent effects against age-related oxidative stress as well as on the gut health and gut-brain axis. Further, we have discussed the key mechanism of action of Lactobacillus strains in the longevity of life, alleviating gut dysbiosis, and improving oxidative stress and inflammation to provide an outline of the role of Lactobacillus strains in restoration of gut microbiota dysbiosis and alleviating certain conditions during ageing. Microbiota-targeted interventions of some characterized strains of probiotic Lactobacillus for the restoration of gut microbial community are considered as a potential approach to improve several neurological conditions. However, very limited human studies are available on this alarmed issue and recommend further studies to identify the unique Lactobacillus strains with potential anti-ageing properties and to discover its novel core microbiome-association, which will help to increase the therapeutic potential of probiotic Lactobacillus strains to ageing.

The study was conducted to screen high 1,2-propanediol produced by Lactobacillus buchneri strains, isolated from baled silages stored for 1 or 2 years, and to evaluate their effects on fermentation quality and aerobic stability of whole-plant corn silage. In total, 31 L. buchneri strains were isolated from alfalfa, whole-plant corn and oat silages. Based on growth performance and 1,2-propanediol and acetic acid production, two strains, L. buchneri 9-2 and L. buchneri 10-1, from alfalfa silage, were further assessed in an ensiling trial on whole-plant corn. The corn silage inoculated with L. buchneri 9-2 or L. buchneri 10-1 had a higher concentration of 1,2-propanediol (34.7 or 34.6 g/kg dry matter (DM)) and acetic acid (47.2 or 45.9 g/kg DM) in comparison with L. buchneri 40788 (reference strain) treated silage (19.5 and 35.9 g/kg DM) after 90 d of fermentation. In addition, these two strains performed better in improving silage aerobic stability relative to control and L. buchneri 40788. The results above indicated that L. buchneri 9-2 and L. buchneri 10-1 could be candidate strains to increase 1,2-propanediol and acetic acid concentrations and improve the aerobic stability of whole-plant corn silage.

Based on the understandings on enrichment rules of marine shale gas in southern China and data obtained from exploration and development in Fuling shale gas field, this article discusses the key controlling factors on shale gas enrichment and their relationships, it also discusses further the theory of Two-Factor Enrichment of marine shale gas in southern China. The bases for shale gas enrichment are shale gas generation and accumulation, the shale gas reservoirs of deep-water shelf are characterized by high TOC, high porosity, high gas contents and high siliceous contents, with high hydrocarbon-generation intensity. The organic pores are rich in shales in favorable for stimulation, so they are the bases for large scale hydrocarbon accumulation. Preservation conditions are vital to the formation and enrichment of shale gas reservoirs, good top and base layers can effectively prevent hydrocarbon from escaping vertically at the beginning of hydrocarbon generation. Shale gas preservation conditions depend on the intensity and duration of tectonic movements, good preservation conditions are key geological factors for shale gas accumulation, shale reservoirs have high gas contents, high porosity and high pressure and are likely to form high yield area of shale gas. Key words: Sichuan Basin, Fuling shale gas field, Lower Silurian, Longmaxi Formation, shale gas, enrichment and high production, controlling factors

This study investigated the antioxidant properties of lactic acid bacteria (LAB) isolated from spontaneously fermented yak milk collected on the Tibetan Plateau. Nine different species of LAB strains with high 2,2-diphenyl-1picrylhydrazyl radical-scavenging activity were screened from 403 isolates, and most of the selected LAB strains exhibited higher antioxidant activity than the reference strains from low-altitude areas. Among the 9 screened strains, L. delbrueckii subsp. bulgaricus F17 showed the greatest probiotic potential due to its high free radical scavenging activity (scavenging 59% OH· and 54% O2−) and high survival rate (58%) within a simulated gastrointestinal tract. After administering the strain to ageing mice induced by d-galactose, the glutathione peroxidase activity in mouse livers and sera and the superoxide dismutase activities in mouse sera and brains increased significantly, while malondialdehyde levels in mouse livers and sera decreased significantly. This unique isolate could be considered a potential antioxidant strain for functional food production.

The objectives of the present study were to screen cholesterol-lowering lactic acid bacteria from traditional fermented Tibetan yak milk, and to evaluate their potential use as cholesterol-reducing probiotics in rats. A total of 115 isolates were evaluated for their cholesterol-lowering and probiotic profiles by in vitro assays, and a strain with good performance in in vitro test was selected to test its probiotic effects in rats fed a high cholesterol diet. Results showed that the strain of L. plantarum Lp3 had a high cholesterol-reducing rate (73.3%) and survival rate in simulated gastrointestinal fluids. Administration of Lp3 to rats fed a high-cholesterol diet promoted notable declines in serum and liver cholesterol and triglycerides levels, and reduced lipid deposition in the cytoplasm of rat’s liver tissue. These results suggest that the strain of L. plantarum Lp3 could be a potential probiotic to treat hyperlipidemia and to be used in functional food.

The present study investigated the species level based microbial community and metabolome in corn silage inoculated with or without homofermentative Lactobacillus plantarum and heterofermentative Lactobacillus buchneri using the PacBio SMRT Sequencing and time-of-flight mass spectrometry (GC-TOF/MS). Chopped whole crop corn was treated with (1) deionized water (control), (2) Lactobacillus plantarum, or (3) Lactobacillus buchneri. The chopped whole crop corn was ensiled in vacuum-sealed polyethylene bags containing 300 g of fresh forge for 90 days, with three replicates for each treatment. The results showed that a total of 979 substances were detected, and 316 different metabolites were identified. Some metabolites with antimicrobial activity were detected in whole crop corn silage, such as catechol, 3-phenyllactic acid, 4-hydroxybenzoic acid, azelaic acid, 3,4-dihydroxybenzoic acid and 4-hydroxycinnamic acid. Catechol, pyrogallol and ferulic acid with antioxidant property, 4-hydroxybutyrate with nervine activity, and linoleic acid with cholesterol lowering effects, were detected in present study. In addition, a flavoring agent of myristic acid and a depression mitigation substance of phenylethylamine were also found in this study. Samples treated with inoculants presented more biofunctional metabolites of organic acids, amino acids and phenolic acids than untreated samples. The Lactobacillus species covered over 98% after ensiling, and were mainly comprised by the L. acetotolerans, L. silagei, L. parafarraginis, L. buchneri and L. odoratitofui. As compared to the control silage, inoculation of L. plantarum increased the relative abundances of L. acetotolerans, L. buchneri and L. parafarraginis, and a considerable decline in the proportion of L. silagei was observed; whereas an obvious decrease in L. acetotolerans and increases in L. odoratitofui and L. farciminis were observed in the L. buchneri inoculated silage. Therefore, inoculation of L. plantarum and L. buchneri regulated the microbial composition and metabolome of the corn silage with different behaviors. The present results indicated that profiling of silage microbiome and metabolome might improve our current understanding of the biological process underlying silage formation.

The influence of mixing alfalfa with whole-plant corn in different proportions on the fermentation characteristics and bacterial community of silage was investigated. Alfalfa and whole-plant corn, harvested at dry matter content of 276.47 and 328.43 g/kg fresh weight, accordingly, were chopped to approximately 2 cm and mixed at ratios of 100:0 (C0, control), 80:20 (C20), 60:40 (C40), 40:60 (C60), 20:80 (C80) and 0:100 (C100) on a fresh weight basis, respectively. Silos of each treatment were produced in triplicate and anaerobically fermented in darkness for 100 days at room temperature (20–21 °C). At silo opening, silage fermentation characteristics and bacterial composition and diversity were analyzed. The C0 silage was weakly preserved, evidenced by a low lactic acid concentration and a high value of pH, acetic acid, propionic acid, butyric acid and ammonia nitrogen. With corn proportion in the mixture increasing from 0% to 40%, silage pH, acetic acid, butyric acid and ammonia nitrogen level decreased, whereas the value of lactic acid and lactic acid to acetic acid ratio increased. The C40, C60, C80 and C100 silages’ Flieg score, used to evaluate the overall fermentation quality, was above 80 and higher than C0 (25) and C20 (61) silages. The C0 silage contained a complex bacterial community at the genus level, consisting mainly of Enterococcus (38.86%), Enterobacteria (20.61%), Rhizobium (8.45%), Lactobacillus (8.15%), Methylobacterium (5.54%) and Weissella (5.24%). As corn percentage increased from 0% to 40%, the relative abundance of desirable Lactobacillus increased and undesirable Rhizobium and Methylobacterium population reduced. With corn proportion in the mixture increasing from 0% to 40%, inclusion of corn to alfalfa at ensiling significantly improved silage fermentation quality and shifted the bacterial community for better silage preservation. Overall, high quality silage was produced when alfalfa was combined with at least 40% whole-plant corn on a fresh weight basis.

The effects of two strains of class IIa bacteriocin-producing lactic acid bacteria, Lactobacillus delbrueckii F17 and Lactobacillus plantarum (BNCC 336943), or a non-bacteriocin Lactobacillus plantarum MTD/1 (NCIMB 40027), on fermentation quality, microbial counts, and aerobic stability of alfalfa silage were investigated. Alfalfa was harvested at the initial flowering stage, wilted to a dry matter concentration of approximately 32%, and chopped to 1 to 2 cm length. Chopped samples were treated with nothing (control, CON), Lactobacillus delbrueckii F17 (F17), Lactobacillus plantarum (BNCC 336943) (LPB), or Lactobacillus plantarum MTD/1 (NCIMB 40027) (LPN), each at an application rate of 1 × 106 colony-forming units/g of fresh weight. Each treatment was ensiled in quadruplicate in vacuum-sealed polyethylene bags packed with 500 g of fresh alfalfa per bag and ensiled at ambient temperature (25 ± 2 °C) for 3, 7, 14, 30, and 60 days. The samples were then subjected to an aerobic stability test after 60 days of ensiling. Compared with the CON silage, the inoculants reduced the pH after 14 days of ensiling. After 60 days, pH was lowest in the LPB-treated silage, followed by the F17 and LPN-treated silages. Inoculation of F17 increased concentrations of lactic acid in silages fermented for 7, 14, 30, and 60 days relative to other treatments, except for the LPN-treated silages ensiled for 30 and 60 days, in which the lactic acid concentrations were similar to that of F17 silage. Application of F17 and LPB decreased the number of yeast and mold relative to CON and LPN-treated silages. Compared with the CON silage, inoculant-treated silages had greater aerobic stability, water-soluble carbohydrate, and crude protein concentrations, and lower neutral detergent fiber, amino acid nitrogen, and ammonia nitrogen concentrations. The LPB-treated silage had the greatest aerobic stability followed by the F17-treated silage. Both class IIa bacteriocin producing inoculants improved alfalfa silage fermentation quality, reduced the growth of yeasts and molds, and improved the aerobic stability of the ensiled forage to a greater extent than the proven LPN inoculant. However, higher crude protein concentration and lower ammonia nitrogen concentration were observed in LPN-treated silage relative to other treatments.

The objective of this study was to estimate cow variability that can be used to determine the optimal sample size for digestibility trials using lactating dairy cows. Experimental design was randomized complete block design having three blocks and three dietary treatments. Three similarly managed nearby intensive farms were considered as blocks, and three diets were formulated to have 0.7, 1.0, and 1.3 neutral detergent fiber (NDF): starch ratio. In each farm, 18 cows were assigned for each dietary treatment and five sample sizes per each treatment group were simulated by simple random sampling of data from 18, 15, 12, 9 and 6 cows respectively. Intake was not affected by diet or sample size (p > 0.05). Estimated cow variability (as standard deviation) for digestibility of dry matter, NDF and starch were 3.8 g/kg, 5.1 g/kg and 3.3 g/kg, respectively. A major implication of this study is that cow variability is greatest for NDF digestibility and the use of a minimum of 12 cows per dietary treatment is adequate to reliably detect treatment effects on the digestibility of NDF, starch and dry matter using cows fed in groups with randomized block design under these experimental conditions.

‘Red Globe’ table grapes are large, edible, seeded fruit with firm flesh that tastes good, but can have poor postharvest shelf-life. This study was conducted to explore the effects of products of Lactobacillus delbrueckii subsp. bulgaricus strain F17 and Leuconostoc lactis strain H52 on ‘Red Globe’ table grapes for the enhancement of shelf-life and improvement of grape quality characteristics during postharvest storage. Strains F17 and H52 were isolated from traditional fermented yak milk obtained in the Qinghai–Tibetan Plateau. Samples from untreated and treated grapes were analyzed for physicochemical, biochemical, and microbiological properties (weight loss, decay rate, pH, total soluble solids content, titratable acidity, total phenols, sensory evaluation, and microbial growth) for 20 days. The results demonstrated that supernatants from both strains significantly reduced weight loss, decay rate, aerobic mesophilic bacteria, and coliform bacteria counts; delayed maturity and senescence of table grapes; and reduced titratable acidity and total phenols. However, the supernatant of strain F17 was more effective and resulted in better sensory evaluations and had a significant inhibitory effect on yeast and molds by day 5. Meanwhile, the supernatant from strain H52 had a significant inhibitory effect on fungi over the whole storage period. In addition, the results of the Pearson correlation analysis suggested that weight loss, decay rate, total soluble solids content, and microorganisms were highly correlated with the sensory evaluation data and quality of postharvest grapes when treated with the products of strain F17. On the basis of these data and sensory organoleptic qualities, the supernatant containing products from strain F17 had the best potential as a biopreservative to improve the postharvest quality of ‘Red Globe’ table grapes.

Pore structures in shales are a main factor affecting the storage capacity and production performance of shale gas reservoirs. Taking Longmaxi Shales in the Jiaoshiba area of the Sichuan Basin as a study object, we systematically study the microscopic pore structures of shales by using Argon-ion polishing Scanning Electron Microscope (SEM), high-pressure mercury injection and low-temperature nitrogen adsorption and desorption experiments. The study results show that: the Longmaxi Shale in this area are dominated by nano-scale pores which can be classified into organic pores, inorganic pores (intergranular pores, intragranular pores, inter-crystalline pores and dissolution pores), microfractures (intragranular structure fractures, interlayer sliding fractures, diagenetic shrinkage joints and abnormal-pressure fractures from organic evolution), among which organic pores and clay mineral pores are predominant and organic pores are the most common; a TOC value shows an obvious positive correlation with the content of organic pores, which account for up to 50% in the lower-quality shales with a TOC of over 2% where they are most developed; microscopic pore structures are very complex and open, with pores being mainly in cylinder shape with two ends open, or in parallel tabular shape with four sides open and 2–30 nm in diameter, being mostly medium pores. On this basis, factors affecting the micropore structures of shales in this area are studied. It is concluded that organic matter abundance and thermal maturity are the major factors controlling the microscopic pore structures of shales, while the effects of clay mineral content are relatively insignificant.