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Biogas is one of the practical vitality sources of energy that can be delivered from numerous sorts of biomass. Biogas production from fresh digestate bacterial crude culture; Providencia alcalifaciens and Alcaligenes aquatilis isolated from municipal wastewater treatment plants located in Port Said, Egypt and identified with 16S rRNA; amended with aquatic macrophytes; Pistia stratiotes and Potamogeton pectinatus, collected from some irrigation canals in Port Said, Egypt as a substrate in the presence of different concentrations of chemically prepared nickel oxide nanoparticles (NiONPs) subjected to anaerobic conditions were successfully investigated. The produced biogas was collected by the water displacement method and subsequently measured using GC/MS analysis. As found in this present work, the optimum NiONPs concentration was 2 ppm for biogas production, where the highest productivity was 42.90 mL and 31.33 mL/3.4 g of P. stratiotes and P. pectinatus with enhancing % 87.91% and 82.38%, respectively compared with the control (without NiONPs) at 30 days of incubation period. Biogas production was slightly greater using P. stratiotes than P. pectinatus particularly with the addition of NiONPs. The present examination may have a noteworthy task in the generation of reasonable biogas amounts utilizing monetary wellsprings of reusing the horrible water system trenches macrophytes and control of environmental defilement issues that may have come about in light of these unfortunate macrophytes.

The issue of the formation of the compound composition of low-molecular-weight organic compounds in aquatic macrophytes, which make up their low-molecular-weight metabolism, has hardly been studied when introducing them into new habitats. The study aims to compare the component composition of the low-molecular-weight metabolome of sago pondweed (Potamogeton pectinatus L.) on the low-molecular-weight organic compounds contained in the essential oil from the invasive population in the Lake Ladoga and the populations from the native range in Astrakhan Region, Russia. Gas chromatography–mass spectrometry was the major research method. Upon the invasion of P. pectinatus into Lake Ladoga, there was a change in the content of various groups of low-molecular-weight organic compounds in the essential oil and a change in the complex of major components. Fatty acids (29.3–40.0%) and ketones (14.5–18.5%) prevailed in the low-molecular-weight metabolome of sago pondweed in the lakes of the native range. Ketones (27.4%) and aldehydes (18.1%) were the main groups in this species inhabiting Lake Ladoga. About a third of the compounds in the composition of the low-molecular-weight metabolome were specific both to the invasive population of the sago pondweed in the Lake Ladoga and to the population from the lakes of the native range. The plasticity of the metabolism of P. pectinatus allows it to adapt to a wide spectrum of abiotic conditions and different biological environments and to settle in new habitats, primarily those under anthropogenic impact.

During a survey of endophytic fungi in aquatic plants collected from Tibet, PR China, a novel species, Ramichloridium endophyticum, was isolated from Potamogeton pectinatus. This novel species differs from other species of the genus Ramichloridium by its finely verrucose, obovoid, ellipsoidal–obovoid and occasionally subglobose conidia. Phylogenetic analysis of the combined sequences of the internal transcribed spacers (ITS) and the translation elongation factor 1-alpha gene (tef1-α) confirmed that the isolated strain represents a member of the genus Ramichloridium. A full description, illustrations and a phylogenetic tree showing the position of R. endophyticum are provided.

Estuarine ecosystems are recipients of anthropogenic stressors released from land-based activities. The aim of the present study was to investigate the ecotoxicological hazards of organic contaminants toward the estuarine copepod Gladioferens pectinatus using acute and chronic testing. Most chemicals demonstrated acute toxicity and influenced development of the copepods. Further research should be conducted to investigate these chemicals and their mixtures using long-term, multigenerational testing to characterize mechanisms of toxicity. Environ Toxicol Chem 2022;41:792-799. © 2022 SETAC.

Boosted by the high temperatures in which vinasse is generated (90 °C–100 °C), this study evaluated the effect of an extreme thermophilic condition (70 °C) on sugarcane vinasse Dark Fermentation (DF) in an Anaerobic Structured Bed Reactor (ASTBR). Four hydraulic retention times (HRT) (19, 15, 12 and 8 h) were evaluated. Higher HRT resulted in a greater H2 production rate (690 mLH2.d−1.L−1), higher yields (1.8 molH2.molGlucose−1) and greater stability. The extreme temperature inhibits microorganisms' extracellular polymer production, thus leading to a disperse growth, preventing excess biomass accumulation, which was previously reported as the main drawback in H2 production at lower temperatures. The ASTBR higher void index is also responsible for lower biomass/solids retention. The H2 production main route was through the lactic/acetic acid pathway, which is highly reliant on the pH of fermentation broth. The main genus involved in H2 production at 70 °C were Clostridium, Pectinatus, Megasphaera and Lactobacillus.

Well validated and reliable biological assays using local and native species are required to characterise the impacts of pollution on ecosystem health. We identified a native estuarine pelagic copepod species suitable for assessing the ecotoxicological impact of anthropogenic contaminants. Gladioferens pectinatus fulfilled the necessary-selection criteria of: wide distribution and abundance across New Zealand estuaries, ease of maintenance in the laboratory, short life cycle, sensitivity to toxicants with different modes of action, and providing reproducibility of biological response to toxicants. Measured endpoints were survival and larval development rate for the nauplii, and survival, realized offspring and total potential offspring for adults. LC50 values for the survival of G. pectinatus exposed to copper, phenanthrene and chlorpyrifos were 170 (143–193), 181.3 (131.3–231.3) and 4.3 (3.8–4.9) µg/L, respectively. The most sensitive chronic endpoint identified for G. pectinatus was the larval development rate, with EC50 values of 49.8 (45–55.3), 31.3 (24.8–44.7) and 1.97 (1.6–2.31) µg/L for copper, phenanthrene and chlorpyrifos, respectively. The acute and chronic responses obtained for G. pectinatus against the three reference toxicants are comparable with those reported for other copepod species and confirm its sensitivity and suitability to assess the toxicity of New Zealand estuarine samples.

Epiphytic bacteria and bacterioplankton affect the plant physiology and nutrient transformation of submerged macrophytes. The community structure of epiphytic bacteria and bacterioplankton is fundamental to understanding their ecological role and, in turn, the effect of macrophytes on bacteria. In this study we compared the composition of epiphytic bacteria in association with Potamogeton pectinatus, as well as that of the surrounding bacterioplankton at different growing stages of P. pectinatus. Proteobacteria, Bacteroidetes, Cyanobacteria, and Actinobacteria were dominant groups in both epiphytic bacteria and bacterioplankton, yet there was a significant discrepancy in the community structure among different growing stages, and bacterioplankton exhibited higher diversity than epiphytic bacteria during the entire growing period. The relative abundance of most bacteria showed opposite trends between epiphytic bacteria and bacterioplankton. Further studies should focus on the underlying interactions between epiphytic bacteria and their host plants.

Contaminants are often at low concentrations in ecosystems and their effects on exposed organisms can occur over long periods of time and across multiple generations. Alterations to subcellular mechanistic pathways in response to exposure to contaminants can provide insights into mechanisms of toxicity that methods measuring higher levels of biological may miss. Analysis of the whole transcriptome can identify novel mechanisms of action leading to impacts in exposed biota. The aim of this study was to characterise how exposures to copper, benzophenone and diclofenac across multiple generations altered molecular expression pathways in the marine copepod Gladioferens pectinatus. Results of the study demonstrated differential gene expression was observed in cultures exposure to diclofenac (569), copper (449) and benzophenone (59). Pathways linked to stress, growth, cellular and metabolic processes were altered by exposure to all three contaminants with genes associated with oxidative stress and xenobiotic regulation also impacted. Protein kinase functioning, cytochrome P450, transcription, skeletal muscle contraction/relaxation, mitochondrial phosphate translocator, protein synthesis and mitochondrial methylation were all differentially expressed with all three chemicals. The results of the study also suggested that using dimethyl sulfoxide as a dispersant influenced the transcriptome and future research may want to investigate it's use in molecular studies. Data generated in this study provides a first look at transcriptomic response of G. pectinatus exposed to contaminants across multiple generations, future research is needed to validate the identified biomarkers and link these results to apical responses such as population growth to demonstrate the predictive capacity of molecular tools.

Background: Thymus species are well-known as medicinal plants. It was aimed to investigate the chemical composition of Thymus pectinatus (TP) and its antioxidant, antimicrobial, antispasmodic, and angiogenic activities.Materials and Methods: After essential oil of TP (EO-TP) was obtained with clevenger distillation system, it was analyzed for chemical composition with GC-MS. To study antispasmodic activity, eight male Wistar albino rats each weighing approximately 250-300 g were used.Results: The results of the analysis revealed 19 components, which equals to 92.93 of the essential oil. The following are the main components; thymol (48.77%), m-cymene (9.15%), isoborneol (5.19%), trans-caryophyllene (4.43%), carvacrol (3.91%) and ϒ-terpinene (3.54%). It has been found that microorganisms subjected to whole all of microbiological tests are highly resistant to EO-TP. 2,2- diphenyl-l-picrylhydrazyl, hydroxyl radical, along with superoxide radical scavenging, and lipid peroxidation says were utilized to show the antioxidant activities of the EO-TP. In measuring its effect, 0.1 mg/mL and 0.5 mg/mL dosage of the EO-TP was applied to the rat ileum as a result of which the magnitude and the frequency of the contractions were observed to be significantly.Conclusion: It was also understood that EO-TP had angiogenic effect upon the vein system of the embryos of chicks. There is a need for further studies to clarify the mechanisms of antimicrobial, antioxidant and angiogenic effects and to determine the constituents of EO-TP responsible from these effects, especially the angiogenic.Keywords: Thymus pectinatus, essential oil, angiogenic, antioxidant, antimicrobial, antispasmodic activity, shell-less chick embryo culture

Potamogeton pectinatusL. is a widespread aquatic species distributed widely in aquatic ecosystems of Iran. In this study, inter simple sequence repeat (ISSR) markers were used to assess the genetic diversity of 35 accessions and 175 individuals ofP. pectinatuscollected from different regions of Iran. In total, 123 polymorphic DNA fragments were amplified from five combinations of ISSR primers. The ISSR based principle coordinate analyses (PCoA) demonstrated four different groups mostly corresponding with their geographic origins (North, Kerman/Fars, Centre and Southwest). The most variable populations were found in the central region of Iran possibly as a consequence of the larger number of samples from that region. The result of molecular variance (AMOVA) attributed 11% of the total genetic variation among and 89% within population variation. The results showed high levels of intra-regional and low inter-regional gene flow between clones, although the Northern accessions were clearly differentiated from the others. There was a low correlation between genetic distance and geographic distance of accessions. The results of STRUCTURE analysis suggested the presence of three genetic groups of this species in Iran, mostly adapted to different ecological conditions. Our results cover one of the gaps of different studies worldwide. In addition, our results confirm high levels of genetic diversity ofP. pectinatusin Iran.

To enhance the hydrogen and methane coproduction potential, three pretreatments (i.e., acid, alkali and cellulase) were investigated during a two-stage anaerobic fermentation using Potamogeton pectinatus biomass. The fluorescence spectral characteristics of the dissolved organic matter (DOM) from the two-stage effluents, coupled with parallel factor analysis, were studied. The maximum hydrogen proportions (42.65%) and production rate (4.1 mL h −1 ) were obtained under the 0.5 mol L −1 HCl pretreatment. The highest methane proportions (52.82%) and production rate (14.2 mL h −1 ) were observed under the 0.5 mol L −1 HCl and 10 mg g −1 cellulase pretreatments, respectively. Combined with fluorescence spectra and parallel factor analysis, three fluorescent components were identified, and the protein-like substances were determined to be dominant. Using the acid pretreatment, the change of the maximum fluorescence intensities in the DOM was the most significant among the three pretreatments, followed by that of the cellulose pretreatment. The result indicated that the macromolecular substances in P . pectinatus can be decomposed by effective pretreatment and thereby enhances the hydrogen and methane coproduction potential. This technique represents a promising method for improving cellulosic biomass biodegradation and green energy coproduction.

Carbon dioxide levels in many estuaries fluctuate and, in several cases, reach extremes much higher than those predicted for oceans by the end of the century. Moreover, estuaries are characterized by natural fluctuations in salinity, and reduced pH, from increased pCO2, exposes estuarine organisms to multiple stresses. Although the effects of low pH on the reproduction of several marine copepod species have been assessed, studies examining effects of pH in estuarine copepod species are extremely scarce. Here, we aim at understanding the reproductive response of Gladioferens pectinatus to the stress posed by both salinity and pH. G. pectinatus was exposed to salinities 2 and 10, at four different pH levels each. Our results show no impairment in the brood size, embryonic development time and hatching success under low pH levels at either salinities. However, at salinity 2, the percentage of nauplii growing into adults significantly decreased at low pH, whereas at salinity 10, no major effect was observed. We argue that the combination of osmoregulation and acidity induced stress response can affect the development of nauplii and copepodites, as well as adult recruitment, likely due to energy reallocation and molting impairment. We also argue that resilience and phenotypic plasticity highly influence the ability of different copepod species and populations to reproduce and grow under stressful combinations of environmental parameters. This study points out the importance of understanding the effects of multiple stresses or parameters on the adaptability of organisms to water acidification.

Wastewater from coconut processing industry contains carbohydrates which are potential substrates for butanol and ethanol fermentation process. In this research, five isolates of anaerobic bacteria were screened from coconut wastewater. To identify the species and solvent production, the morphological characterization, 16S rRNA gene identification and biochemical test were performed. It was discovered that the isolate COCON2 belongs to the species Pectinatus frisingensis with 16S rRNA gene sequence identity of 98%, whereas COCON4, COCON9 and COCON11 are closely related to Pectinatus portalensis (with 16S rRNA sequence identity percentage of 98, 99 and 99% respectively). As for COCON6, it is similar to Klebsiella oxytoca with 98% 16S rRNA sequence similarity. The solvent production of Pectinatus spp. under anaerobic condition from 20 g/L mannose in 30 mL synthetic medium showed acetate as the main product (1.877–2.146 g/L). In conclusion, naturally selected bacteria have the ability to convert sugar into acetate and ethanol which are metabolites from cellular respiration in optimum condition.

Obligate anaerobic bacteria from the genus Pectinatus have been known to cause beer spoilage for over 40 years. Whole genome sequencing was performed on eleven beer spoilage strains (nine Pectinatus frisingensis, one Pectinatus cerevisiiphilus and one Pectinatus haikarae isolate), as well as two pickle spoilage species (Pectinatus brassicae MB591 and Pectinatus sottacetonis MB620) and the tolerance of all species to a range of environmental conditions was tested. Exploration of metabolic pathways for carbohydrates, amino acids and vitamins showed little difference between beer spoilage- and pickle spoilage-associated strains. However, genes for certain carbohydrate- and sulphur-containing amino acid-associated enzymes were only present in the beer spoilage group and genes for specific transporters and regulatory genes were uniquely found in the pickle spoilage group. Transporters for compatible solutes, only present in pickle-associated strains, likely explain their experimentally observed higher halotolerance compared to the beer spoilers. Genes involved in biofilm formation and ATP Binding Cassette (ABC) transporters potentially capable of exporting hop-derived antimicrobial compounds were found in all strains. All species grew in the presence of alcohol up to 5% alcohol by volume (ABV) and hops extract up to 80 ppm of iso-α-acids. Therefore, the species isolated from pickle processes may pose novel hazards in brewing.

© 2019 The Royal Society of Chemistry. Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS), in combination with Biotyper software, is a rapid, high-throughput, and accurate method for the identification of microbes. Microbial outbreaks in a brewery present a major risk for companies as it can lead to cost-intensive recalls and damage to the brand reputation. MALDI-TOF MS has been implemented into a brewery setting for quality control practices and the identification of beer spoilage microorganisms. However, the applicability of this approach is hindered by compatibility issues associated with mixed cultures, requiring the use of time-consuming selective cultivation techniques prior to identification. We propose a novel, low-cost approach based on the combination of inertial microfluidics and secondary flows in a spiral microchannel for high-throughput and efficient separation of yeasts (Saccharomyces pastorianus and Saccharomyces cerevisiae) from beer spoilage microorganisms (Lactobacillus brevis and Pediococcus damnosus). Flow rates were optimised using S. pastorianus and L. brevis, leading to separation of more than 90% of the L. brevis cells from yeast. The microorganisms were then identified to the species level using the MALDI-TOF MS platform using standard sample preparation protocols. This study shows the high-throughput and rapid separation of spoilage microorganisms (0.3-3 μm) from background yeast (5 μm) from beer, subsequent identification using MALDI Biotyper, and the potential applicability of the approach for biological control in the brewing industry.

Although adhesion of acetic and lactic acid bacteria and yeasts have been extensively studied in a wide range of experimental and theoretical approaches, no attention has been paid to adhesion of anaerobic beer spoilage bacteria to solid materials. This work focuses on physicochemical aspects of adhesion of Megasphaera cerevisiae and Pectinatus frisingensis to stainless steel. The results, based on experimental characterization of surface properties, contact angle and zeta potential measurements, are used in modeling the surface interactions (thermodynamic and colloidal models) resulting in a quantitative prediction of interactions. The model predictions are compared with experimental adhesion tests in order to identify physicochemical forces controlling adhesion. The results revealed that the most significant adhesion occurred at a low ionic strength (10 mM) and an acidic to neutral pH. Under these conditions cell/stainless steel interactions were more pronounced for M. cerevisiae than for P. frisingensis and were influenced mostly by electrostatic attractions between surfaces. Overall, the lowest rate of adhesion between cells and stainless steel was observed at a low ionic strength and an alkaline pH. At high ionic strength (500 mM), adhesion was more pronounced for P. frisingensis, demonstrating the importance of Liftshitz-van der Waals interactions.

Traditionally, beer has been recognised as a beverage with high microbiological stability because of the hostile growth environment posed by beer and increasing attention being paid to brewery hygiene. However, the microbiological risk has increased in recent years because of technological advances toward reducing oxygen in beers, besides the increase in novel beer styles production, such as non-pasteurised, flash pasteurised, cold sterilised, mid-strength, and alcoholic-free beer, that are more prone to spoilage bacteria. Moreover, using innovative beer ingredients like fruits and vegetables is an added cause of microbial spoilage. To maintain quality and good brand image, beer spoilage microorganisms are a critical concern for breweries worldwide. Pectinatus and Megasphaera are Gram-negative bacteria mostly found in improper brewing environments, leading to consumer complaints and financial losses. Because of the lack of compiled scientific knowledge on Pectinatus spoilage ability, this review provides a comprehensive overview of the occurrence, survival mechanisms, and the factors affecting beer spoilage Pectinatus species in the brewing process., This study was supported by the grants AGL2015-64522-C2-1-R (Spanish Ministry of Science and Innovation), and ALIBIRD-CM 2020 P2018/BAA-4343 (Comunidad de Madrid). M. R-S thanks the “President of the Republic Fellowship” from the Ministry of Education of the Republic of Peru.

The UV-filter benzophenone and the anti-inflammatory diclofenac are commonly detected in the environment. The aim of this study was to assess the multigenerational effects of chronic exposure to low concentrations of these chemicals on toxicity and DNA methylation levels in the copepod Gladioferens pectinatus. Acute toxicity tests were conducted to determine the sensitivity of G. pectinatus to the chemicals. All chemicals impacted breeding, hatching and egg viability. Diclofenac (1 mg.L-1) reduced the number of eggs per gravid female. Benzophenone (0.5 mg.L-1) decreased egg hatching success. Exposure to the reference toxicant copper (0.02 mg.L-1) led to unsuccessful hatching. Effects on DNA methylation was estimated by the percentage of 5- methylcytosine. The treatments resulted in strong differences in DNA methylation with increased methylation in the exposed animals. The two chemicals impacted both egg viability and the induction of differential DNA methylation, suggesting potential intra- and trans-generational evolutionary effects.

Objetivo: Identificar morfológicamente microalgas del lago Bosque Azul, Montebello, Chiapas.Diseño/metodología/aproximación: Las muestras se recolectaron en abril de 2018 usando una red cónica por arrastre horizontal durante cinco minutos a 30 cm por debajo de la superficie de agua. Las muestras fueron inoculadas en tubos de ensayo en los medios de cultivo Guillard F/2 y BBM para observar la presencia de microalgas bajo microscopio en objetivos de 10X y 40X. Para el aislamiento se aplicóla técnica de estriado y diluciones seriadas en relación 1:10, usando lámparas LED blancas de 18 watts como fuente de iluminación, un fotoperiodo de 12:12 y temperatura de 25 °C?2. Para la identificaciónmorfológica se realizaron preparaciones semipermanentes para su observación en dos tipos de microscopio uno de contraste de fases y otro de interferencia diferencial (DIC) en objetivos de 20X, 40X y 100X. Las imágenes obtenidas se compararon con bibliografía especializada de acuerdo a su grupo microalgal para la identificación morfológica.Resultados: Se logró aislar e identificar morfológicamente dos microorganismos de la laguna Bosque Azul, perteneciente al Parque Nacional Lagunas de Montebello una microalga Pectinodesmus pectinatus y una cianobacteria Limnothrix planctónica.Limitaciones del estudio/implicaciones: Es necesario investigar las implicaciones de estos grupos algales en el estado trófico del lago Bosque Azul, así como la posible toxicidad que pueda causar Limnothrixplanctónica en los peces del lago.Hallazgos/conclusiones: Existen reportes de acumulación de lípidos en Pectinodesmus pectinatus que podrían ser utilizados para la producción de biocombustibles como el biodiesel. Por otro lado, Limnothrixplanctónica ha sido reportada como productora de metabolitos con potencial biotecnológico en la producción de lípidos, pigmentos, carbohidratos y exopolisacáridos. Ambos microorganismos son los primeros reportes en Chiapas y en el caso de Limnothrix planctónica, el primer reporte en México.

Lucinidae clams harbor gammaproteobacterial thioautotrophic gill endosymbionts that are environmentally acquired. Thioautotrophic lucinid symbionts are related to metabolically similar symbionts associated with diverse marine host taxa and fall into three distinct phylogenetic clades. Most studies on the lucinid–bacteria chemosymbiosis have been done with seagrass-dwelling hosts, whose symbionts belong to the largest phylogenetic clade. In this study, we examined the taxonomy and functional repertoire of bacterial endosymbionts at an unprecedented resolution from Phacoides pectinatus retrieved from mangrove-lined coastal sediments, which are underrepresented in chemosymbiosis studies. The P. pectinatus thioautotrophic endosymbiont expressed metabolic gene variants for thioautotrophy, respiration, and nitrogen assimilation distinct from previously characterized lucinid thioautotrophic symbionts and other marine symbionts. At least two other bacterial species with different metabolisms were also consistently identified in the P. pectinatus gill microbiome, including a Kistimonas-like species and a Spirochaeta-like species. Bacterial transcripts involved in adhesion, growth, and virulence and mixotrophy were highly expressed, as were host-related hemoglobin and lysozyme transcripts indicative of sulfide/oxygen/CO2 transport and bactericidal activity. This study suggests the potential roles of P. pectinatus and its gill microbiome species in mangrove sediment biogeochemistry and offers insights into host and microbe metabolisms in the habitat.

Gram negative aerobic bacteria such as Acetic Acid Bacteria, which include Acetobacter and Gluconobacter, have historically caused significant problems to brewers. Although incidences of spoilage have recently reduced as a result of improvements in beer packaging, these bacteria are still a concern in dispense systems in pub breweries, public houses and cask conditioned beers. Gram negative facultative bacteria of the genus Zymomonas can spoil primed cask conditioned beer and cider. There is a wide range of Enterobacteraeceace which are found within brewery environments and they serve as indicator microorganisms for hygiene and sanitation. Gram negative strictly anaerobic bacteria such as Pectinatus and Megasphaera have recently emerged as a significant threat due to the improvement in reduction of oxygen levels in beer and an increase in production of unpasteurised beer. Pectinatus and Megasphaera are sensitive to routine cleaning agents used in breweries, but they can survive and proliferate in biofilms eventually causing spoilage of beer. This review focuses on Gram negative aerobic, facultative anaerobic and strictly anaerobic brewery related spoilage bacteria.

Fermented cucumber spoilage (FCS) characterized by rising pH and the appearance of manure- and cheese-like aromas is a challenge of significant economical impact for the pickling industry. Previous culture-based studies identified the yeasts Pichia manshurica and Issatchenkia occidentalis, 4 Gram-positive bacteria, Lactobacillus buchneri, Lactobacillus parrafaraginis, Clostridium sp., and Propionibacterium and 1 Gram-negative genus, Pectinatus, as relevant in various stages of FCS given their ability to metabolize lactic acid. It was the objective of this study to augment the current knowledge of FCS using culture-independent methods to microbiologically characterize commercial spoilage samples. Ion Torrent data and 16S rRNA cloning library analyses of samples collected from commercial fermentation tanks confirmed the presence of L. rapi and L. buchneri and revealed the presence of additional species involved in the development of FCS such as Lactobacillus namurensis, Lactobacillus acetotolerans, Lactobacillus panis, Acetobacter peroxydans, Acetobacter aceti, and Acetobacter pasteurianus at pH below 3.4. The culture-independent analyses also revealed the presence of species of Veillonella and Dialister in spoilage samples with pH above 4.0 and confirmed the presence of Pectinatus spp. during lactic acid degradation at the higher pH. Acetobacter spp. were successfully isolated from commercial samples collected from tanks subjected to air purging by plating on Mannitol Yeast Peptone agar. In contrast, Lactobacillus spp. were primarily identified in samples of FCS collected from tanks not subjected to air purging for more than 4 mo. Thus, it is speculated that oxygen availability may be a determining factor in the initiation of spoilage and the leading microbiota.

The microbial basis of acidification process during spontaneous cheese whey wastewater fermentation was decrypted by implementing both culture-dependent and culture-independent techniques. Lac tobacillus and Bifidobacterium were the predominant taxa among the microbiota growing on MRS (deMan, Rogosa, and Sharpe), while Kazachstania unispora and Dekkera anomala yeast species were also isolated. Almost all Lactobacillus isolates were heterofermentative that could ferment glucose and lactose, with most of them being related to Lactobacillus hilgardii (99.0–100 % similarity). By employing fluorescence techniques, the dominance of long crescent-shaped bacteria in the acidogenic sludge was observed. Temperature gradient gel electrophoresis (TGGE), clone library, and next-generation sequencing techniques revealed the dominance of Selenomonas lacticifex. Based on Illumina data, Selenomonas in the continuous stirred-tank reactor (CSTR) represented 70.13 ± 4.64 % of the bacterial reads, while other Veillonellaceae taxa (Megasphaera and Pectinatus) represented a notable proportion (6.54 %). Prevotella was only detected by Illumina sequencing as an important constituent of the microbial population (14.97 ± 1.71 %). Budding yeasts represented 97 % of the fungal population in the CSTR, with Yarrowia strains representing 88.85 ± 5.52 % of the fungal reads. Spontaneous cheese whey acidification can favor the dominance of rumen bacteria and here was driven by the rarely reported S. lacticifex-type fermentation, which should be taken into consideration during evaluation of acidogenesis in process simulation and modelling. Moreover, the important nervonic acid content detected indicates that acidogenic sludge can be used as a source for the production of high value-added biomedical substrates.

Submerged macrophyte detritus is a major component of the organic matter entering shallow lakes. Plant litter decomposition is a complex process that is mediated by microorganisms and some invertebrates. However, the role that aquatic organisms play in the decomposition of macrophytes in shallow subtropical lakes is unclear. This study compared the decomposition rates of Potamogeton pectinatus and Chara zeylanica in a shallow lake (southern Brazil) and assessed the fungal biomass and the macroinvertebrate community associated with the detritus. Aliquots of both species were incubated in litter bags and placed in the lake. After 1, 7, 20, 40, 60, and 80 days of incubation, one set of litter bags was removed from the lake. In a laboratory, plant material was washed for the determination of decomposition rates, chemical characterisation, and quantification of microorganisms and invertebrates. After 80 days of incubation, there was no C. zeylanica detritus, with a decomposition that was four times faster than that of P. pectinatus . The chemical composition was also different between the two detritus, with P. pectinatus showing a higher concentration of nitrogen, phosphorus, organic matter, polyphenols, and carbon. The fungal biomass was similar between the two species. In total, 7502 invertebrates belonging to 27 taxa were sampled in this study. The composition and abundance of invertebrates was different between the two species. In conclusion, the chemical structure of the macrophyte species studied was important for the microorganisms’ and invertebrates’ colonisation. In addition, leaching had an important function in the initial degradation process.

Variation in seed weight is common within and among plant species, but few studies have attempted to document the pattern of seed weight and germination attributes for aquatic macrophytes at a large scale. This study examined within-species variation in seed weight and germination attributes and the effects of environmental factors on seed traits of the submerged plant Potamogeton pectinatus in the arid zone of northwest China. Our results showed that the average seed weight was 0.24 g per 100 seeds with a coefficient of variation (CV) of 28.4% among the eight P. pectinatus populations. The total germination fraction of seeds of P. pectinatus was relatively poor, less than 35% in seven P. pectinatus populations, and the lowest germination percentage found was only 2%. There were significant differences in seed weight, time to onset of germination, and total germination fraction among the eight different populations. Hierarchical partitioning analysis showed a strongly positive correlation between seed weight and water temperature and pH. Seed weight and the maternal environmental factors significantly affected both time to initiation of germination and total germination fraction. Our results suggest that (1) seed weight variation in P. pectinatus primarily is the result of temperature variation during fruit development; (2) relatively poor germination fraction suggests that seeds are relatively unimportant in the short-term survival of populations and that it may be another adaptive trait allowing plants to take place in the right place and at the right time, especially in harsh environment; and (3) variation in seed germination traits should be determined by local environmental and intrinsic factors that interact in a complex fashion.

A new green synthesis method for the preparation of a silver–reduced graphene oxide (Ag–RGO) nanocomposite using Potamogeton pectinatus (Po) plant extract is introduced. The size, morphology and crystallinity of the as-prepared nanomaterials were studied with an explanation for the role of Po in the synthesis. A preliminary antibacterial experiment was developed to ensure the enhanced antibacterial effect of the Ag–RGO nanocomposite. The antibacterial measurements were done using the colony counting method. The results indicated that the majority of the silver nanoparticles “AgNPs” were formed in a spherical shape with small sizes ranging from 11 to 20 nm. IR spectroscopy results indicated the role of amine and hydroxyl groups from Po in the reduction and capping processes. The preliminary antibacterial examination ensured the enhanced antibacterial effect of the Ag–RGO nanocomposite.

The development and evaluation of a 6-hours laboratory class, based on capillary electrophoresis (CE) and the detection of microbial contaminants, is described. It can be easily scaled up or down, to suit class sizes up to 188 and completed in a shorter time scale. CE uses narrow-bore fused-silica capillaries to separate a complex array of large and small molecules. A laboratory exercise has been devised to illustrate how CE-based genetic analysis system processes DNA fragment analysis to detect three microbial contaminants. The protocol is relatively inexpensive and uses standard molecular biology reagents and equipment. © 2018 by The International Union of Biochemistry and Molecular Biology, 46(3):279-284, 2018.

Strictly anaerobic bacteria capable of spoiling beer or contaminating brewer's yeast belong to the genera Megasphaera, Pectinatus, Selenomonas and Zymophilus. This article gives an overview of basic morphological and physiological properties of this group of bacteria, describes the sites of their occurrence in the brewing operation and their ability to spoil beer. It also describes various methods for detection and identification of these microbes - cultivation methods, methods based on PCR, MALDI-TOF MS, and others.Strictly anaerobic bacteria capable of spoiling beer or contaminating brewer's yeast belong to the genera Megasphaera, Pectinatus, Selenomonas and Zymophilus. This article gives an overview of basic morphological and physiological properties of this group of bacteria, describes the sites of their occurrence in the brewing operation and their ability to spoil beer. It also describes various methods for detection and identification of these microbes - cultivation methods, methods based on PCR, MALDI-TOF MS, and others.

Allelopathic effects of submerged macrophytes against algae are affected by many environmental factors which can only be measured one by one by traditional methods. Box-Behnken design of response surface methodology was used to optimize three environmental factors (temperature, light intensity and total dissolved solids) of allelopathic effects of Potamogeton pectinatus against Microcystis aeruginosa at the same time. By solving the regression equation and analyzing the response surface contour plots, the optimal conditions of the relatively inhibitory rate of Microcystis aeruginosa were that the temperature was 23°C, the light intensity was 2,700,lx and the total dissolved solids were 4,415,mg/L. Under these conditions, the optimal value of relatively inhibitory rate of Microcystis aeruginosa was 81.9%. According to validation experiments, the results of analysis indicated that the experimental values fitted well with the predicted ones.

Aims In recent years, beer-spoilage cases from strictly anaerobic bacteria have risen in frequency, in connection with the production of non-pasteurized, non-alcohol and low-alcoholic beers and with the lowering of dissolved oxygen in the packaged beer. Selenomonas lacticifex, found in brewer's yeast and in biofilms covering some surfaces in brewery bottling area, is considered to be a beer-spoilage organism. This study aims to develop S. lacticifex-specific PCR assay. The objective of this study was also evaluation of the specificity and reproducibility of the developed PCR assay in real brewery samples. Methods and Results Three primers (one forward and two reverse) were designed for identification of the strictly anaerobic bacterium S. lacticifex on the basis of the species-specific sequences of the 16S rDNA region. The specificity of the primers was tested against 44 brewery-related non-target micro-organisms that could potentially occur in the same brewery specimens. None of the primer pairs amplified DNA from any of the non-S. lacticifex strains tested including genera from the same family (Pectinatus, Megasphaera, Zymophilus) and the closely related species Selenomonas ruminantium, showing thus 100% specificity. Conclusions The PCR assay developed in this study enables the detection of the strictly anaerobic bacterium S. lacticifex in real brewery samples including pitching yeast. Significance and Impact of the Study Selenomonas lacticifex-specific PCR assay developed in this study allows for the extension of the spectra of detected beer-spoilage micro-organisms in brewing laboratories and thus lowering the risk of contamination of the final product.