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Cyanobacteria hold promise for simultaneous carbon capture and chemicals production, but the regulation and effect of nitrogen (N) and phosphorus (P) remains unclear. This study investigates major productions of glycogen, protein, and C-phycocyanin (C-PC) in Cyanobacterium aponinum PCC10605 under different N/P levels, alongside changes in light and CO 2 . Increasing nitrate (NO 3 - ) from 2 to 6 mM resulted in a 9.7-fold increase in C-PC and reduced glycogen to 8.9 %. On the other hand, elevating phosphorus from 0.1 to 2 mM under limited nitrogen enhanced biomass and glycogen through the upregulation of carbonic anhydrase, ADP-glucose pyrophosphorylase, and glycogen phosphorylase. Changes in phosphorus levels and CO 2 inlet concentrations affected metabolites accumulation and carbon capture efficiency, leading to the best condition of 76 % uptake capacity in direct air capture (DAC). All findings underscore the trade-off between glycogen and protein, representing the importance of N/P levels in nutrient modulation of PCC10605., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The pursuit of carbon neutrality goals has sparked considerable interest in expanding bioplastics production from microbial cell factories. One prominent class of bioplastics, polyhydroxyalkanoates (PHA), is generated by specific microorganisms, serving as carbon and energy storage materials. To begin with, a native PHA producer, Cupriavidus necator (formerly Ralstonia eutropha) is extensively studied, covering essential topics such as carbon source selection, cultivation techniques, and accumulation enhancement strategies. Recently, various hosts including archaea, bacteria, cyanobacteria, yeast, and plants have been explored, stretching the limit of microbial PHA production. This review provides a comprehensive overview of current advancements in PHA bioproduction, spanning from the native to diversified cell factories. Recovery and purification techniques are discussed, and the current status of industrial applications is assessed as a critical milestone for startups. Ultimately, it concludes by addressing contemporary challenges and future prospects, offering insights into the path towards reduced carbon emissions and sustainable development goals., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors are grateful for the financial support received from the Ministry of Science and Technology (MOST 111-2221-E-006-012-MY3) and National Science and Technology Council (NSTC 112-2218-E006-022) in Taiwan., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Chlorella sorokiniana (CS) is a prominent microalga with vast potential as a biocarrier for carbon mitigation toward a green process. However, challenges remain in achieving high biomass levels and production rates. Therefore, a systematic feeding strategy using 4-aminobutyric acid (GABA) and CRISPR technology was applied to improve microalgal productivity. At first, GABA increased protein content by 1.4-fold, while intermittent supplementation during cultivation resulted in a 1.58-fold and 2.13-fold increase in biomass and pigment content, respectively. Under halophilic conditions, the optimal approach involved repeated feeding of 5 mM GABA at the initial and mid-log phases of growth, resulting in biomass, protein, and pigment levels of 6.74 g/L, 3.24 g/L, and 49.87 mg/L. CRISPRa mediated glutamate synthase and using monosodium glutamate (MSG) as a cheap precursor for GABA has effectively enhanced the biomass, protein, and lutein content, thus offers a cost-effective approach to commercialize high-valued chemical using algae towards a low-carbon paradigm., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors are grateful for the financial support received from the Ministry of Science and Technology (MOST 110-2221-E-006-030-MY3 and MOST 111-2221-E-006-012-MY3) and National Science and Technology Council (NSTC 112-2218-E006-022) in Taiwan., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Microbial biomanufacturing is a promising approach to produce high-value compounds with low-carbon footprint and significant economic benefits. Among twelve "Top Value-Added Chemicals from Biomass", itaconic acid (IA) stands out as a versatile platform chemical with numerous applications. IA is naturally produced by Aspergillus and Ustilago species through a cascade enzymatic reaction between aconitase (EC 4.2.1.3) and cis-aconitic acid decarboxylase (EC 4.1.1.6). Recently, non-native hosts such as Escherichia coli, Corynebacterium glutamicum, Saccharomyces cerevisiae, and Yarrowia lipolytica have been genetically engineered to produce IA through the introduction of key enzymes. This review provides an up-to-date summary of the progress made in IA bioproduction, from native to engineered hosts, covers in vivo and in vitro approaches, and highlights the prospects of combination tactics. Current challenges and recent endeavors are also addressed to envision comprehensive strategies for renewable IA production in the future towards sustainable development goals (SDGs)., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors are grateful for the financial support received from the Ministry of Science and Technology (MOST 111-2221-E-006-012-MY3 and MOST 110-2221-E-006-030-MY3) in Taiwan., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Microalgae are widely recognized as a promising bioresource for producing renewable fuels and chemicals. Microalgal biorefinery has tremendous potential for incorporation into circular bioeconomy, including sustainability, cascading use, and waste reduction. In this study, genetic engineering was used to enhance the growth, lipid and lutein productivity of Chlamydomonas reinhardtii including strains of CC400, PY9, pCHS, and PG. Notably, CRISPRi mediated on phosphoenolpyruvate carboxylase (PEPC1) gene to down-regulate the branch pathway from glycolysis to partitioning more carbon flux to lipid was explored under meso-thermophilic condition. The best chassis PGi, which has overexpressed chaperone GroELS and applied CRISPRi resulting in the highest biomass of 2.56 g/L and also boosted the lipids and lutein with 893 and 23.5 mg/L, respectively at 35°C. Finally, all strains with CRISPRi exhibited higher transcriptional levels of the crucial genes from photosynthesis, starch, lipid and lutein metabolism, thus reaching a CO 2 assimilation of 1.087 g-CO 2 /g-DCW in mixotrophic condition., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors are grateful for the financial support received from the Ministry of Science and Technology (MOST 110-2221-E-006-030-MY3 and NSTC 111-2221-E-006-012-MY3) in Taiwan., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Sophisticated genetic engineering enables microbial hosts to derive high-value aromatics in a green manner. Ferulic acid (FA) is one of the noteworthy aromatics due to its potent pharmacokinetic properties. However, the current approaches to FA biosynthesis still decamp from time- and cost-effectiveness. Herein, FA pathway was artificially reconstructed in Escherichia coli using modular designs. Comprehensive screening of E. coli lineages was reckoned for efficient synthesis of p-coumaric acid (pCA) as a precursor and FA eventually. The modular design was further advanced by harboring tyrosine transporter, adapting the heterologous codon, utilizing pCA symporter, and enriching FADH 2 cofactor pools via in vivo regeneration. Taken together with simultaneous optimization of culture condition, a remarkable FA yield of 972.6 mg/L with 89.4 % conversion was achieved in 48 h, circumventing the time-consuming issue. Moreover, this study successfully exported inexpensive precursor from spent coffee ground for the first time, paving the economical way of FA biosynthesis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Carbon dioxide is the major greenhouse gas and regards as the critical issue of global warming and climate changes. The inconspicuous microalgae are responsible for 40% of carbon fixation among all photosynthetic plants along with a higher photosynthetic efficiency and convert the carbon into lipids, protein, pigments, and bioactive compounds. Genetic approach and metabolic engineering are applied to accelerate the growth rate and biomass of microalgae, hence achieve the mission of carbon neutrality. Meanwhile, CRISPR/Cas9 is efficiently to enhance the productivity of high-value compounds in microalgae for it is easier operation, more affordable and is able to regulate multiple genes simultaneously. The genetic engineering strategies provide the multidisciplinary concept to evolute and increase the CO 2 fixation rate through Calvin-Benson-Bassham cycle. Therefore, the technologies, bioinformatics tools, systematic engineering approaches for carbon neutrality and circular economy are summarized and leading one step closer to the decarbonization society in this review., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors are grateful for the financial support received from the Ministry of Science and Technology to I-Son Ng (MOST 111-2221-E-006-012-MY3 and MOST 110-2221-E-006-030-MY3) and to Tse-Min Lee (MOST 110-2311-B-110 -003, MOST 111-2311-B-110-002, MOST 111-2923-B-110 -001-MY2, and MOST 110-2622-E-110-016) in Taiwan., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Human carbonic anhydrase II (hCAII) is a rapid-acting zinc-metalloenzyme that catalyzes CO 2 hydration reversibly, with encouraging applications in carbon capture, sequestration, and utilization (CCSU). However, biocatalyst durability is a major challenge. Herein, hCAII is emphasized in 4 different Escherichia coli strains and designated under dual promoters from sigma factor 70 (σ 70 ) and heat shock protein (HSP70A) to suppress the usage of inducer and stimulate activity in heat environments. As a result, hCAII under high-efficient dual promoters regulation retained high residual activity in CO 2 biomineralization of 68.8 % after 4 cycles at 40 °C. Moreover, co-expression of CA C9 with lysine decarboxylase (CadA) simultaneously sequestered CO 2 release up to 95.7 % and increased cadaverine titer from 18.0 to 36.7 g/L by using E. coli MG1655. The remnant biomass from cadaverine synthesis sustained converting CO 2 to 57.9 mg-CaCO 3 . Thus, the dual promoters design demonstrated the promising potential for CCSU through simultaneous CO 2 utilization and cadaverine synthesis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Sulfurihydrogenibium yellowstonense carbonic anhydrase (SyCA) is a well-known thermophilic CA for carbon mineralization. To broaden the applications of SyCA, the activity of SyCA was improved through stepwise engineering and in different cultural conditions, as well as extended to co-expression with other enzymes. The engineered W3110 strains with 4 different T7 RNA polymerase levels were employed for SyCA production. As a result, the best strain WT7L cultured in modified M9 medium with temperature shifted from 37 to 30 °C after induction increased SyCA activity to 9122 U/mL. The SyCA whole-cell biocatalyst was successfully applied for carbon capture and storage (CCS) of CaCO 3 . Furthermore, SyCA was applied for low-carbon footprint synthesis of 5-aminolevulinic acid (5-ALA) and cadaverine (DAP) by coupling with ALA synthetase (ALAS) and lysine decarboxylase (CadA), suppressing CO 2 release to -6.1 g-CO 2 /g-ALA and -2.53 g-CO 2 /g-DAP, respectively. Harnessing a highly active SyCA offers a complete strategy for CCSU in a green process., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors are grateful for the financial support received from the Ministry of Science and Technology (MOST 111–2221-E-006–012-MY3 and MOST 110–2221-E-006–030-MY3) in Taiwan., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Chlamydomonas reinhardtii is a model microalga that has a higher growth rate and produces high levels of lutein and lipids, but biomass production is limited. Carbonic anhydrase (CA) converts atmospheric CO 2 to bicarbonate which is crucial for carbon-concentrating mechanism (CCM) in microalgae and boosts cell density. Therefore, C. reinhardtii harboring the heterologous CA from Mesorhizobium loti (MlCA) and Sulfurihydrogenibium yellowstonense (SyCA) were explored to increase CO 2 capture and utilization (CCU) through different culture devices. Genetically modified C. reinhardtii was able to grow from mixotrophic to autotrophic conditions. Subsequently, biomass, lutein, and lipid were maximized to OD 680 of 4.56, 21.32 mg/L and 672 mg/L using photo-bioreactor (PBR) with 5% CO 2 . Moreover, CO 2 assimilation rate was 2.748 g-CO 2 /g-DCW and 2.792 g-CO 2 /g-DCW under mixotrophic and autotrophic conditions, respectively. The biomass accumulation correlated with CA activity. In addition, the transcript levels of major genes in metabolic pathways of lutein and lipid were dramatically increased., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The 4-aminobutyric acid (GABA) is important to produce bio-nylon 4 in biorefineries. First, a glutamate decarboxylase (GAD) was propagated in three different Escherichia coli strains to achieve 100% conversion from 1 M monosodium glutamate after optimization of the process. To make the process greener and more efficient, in situ CO 2 adaptation and citrate feeding strategies to maintain the optimal pH value and 498 g/L of GABA was obtained. However, the process releases the equivalent amount of CO 2 . Therefore, CO 2 generated from GABA production was completely sequestered in sodium hydroxide to form bicarbonate and applied in a coupling culture of Chlorella sorokiniana (CS) or Chlorella vulgaris (CV) to increase the biomass when combined with sodium bicarbonate and carbonic anhydrase. Further improvement of 1.65-fold biomass and 1.43-fold lipid content were occurred when supplying GABA to the culture. This integrative process provided the highest GABA production rate without CO 2 release, forming an eco-friendly and carbon-neutral technology., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

A halo-tolerant Cyanobacterium aponinum PCC 10605 was applied for the first time to produce high-level C-phycocyanin (C-PC). Combined with chemical extraction with sodium phosphate buffer and physical treatment using high pressure homogenization, a higher titer of C-PC was achieved. The culture conditions were optimized by mixing nitrate and ammonia ions, 2% carbon dioxide, and conditional light intensity. Thus, strain PCC10605 produced the highest titer C-PC of 0.652 g/g-DCW in the N1A2 medium with 10% light intensity and 16:8 light-period on day 7. PCC10605 accumulated 0.51 g-CPC/g-DCW at 20 g/L NaCl, while it grew normally in seawater with 30 g/L salinity, thus confirmed that PCC10605 was halo-tolerant strain. Besides, PCC10605 survived in 0.12 g/L phosphate medium that has never been reported. Finally, the purified C-PC exhibited DPPH, superoxide scavenging activity and antibacterial activity, which displayed 87.6%, and 18.7% removal of free radical, and 1.98 cm of inhibition zone for Escherichia coli., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

This work aimed to study the efficiency of polyvinyl-alcohol-immobilized Actinobacillus succinogenes ATCC55618 for succinic acid (SA) production. Batch fermentation (pH 7, 45% CO 2 gas at 0.04 vvm) using glucose (40 g L -1 ) resulted in SA titer, 26.7 g L -1 ; productivity, 3.33 g L -1 h -1 ; yield, 0.621 g g - 1. Fed-batch mode with cyclic extrication of SA from the medium markedly enhanced the yield to 0.699 g g -1 and concentration to 59.5 g L -1 . Batch fermentation using sugars derived from Chlorella vulgaris ESP-31 without yeast extract gave a SA productivity, concentration, and yield of 1.82 g L -1 h -1 , 36.1 g L -1 , and 0.720 g g - 1, respectively. Furthermore, continuous fermentation (at 6 h HRT) with microalgal sugar improved the productivity and yield to 3.53 g L -1 h -1 and 0.62 g g -1 , respectively, which is comparable to those obtained by using glucose. This study reports the highest productivity for SA fermentation using microalgae-derived sugars., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Microalga served as the promising bioresources due to the high efficiency of carbon dioxide conversion. However, the application of microalga is still restricted by low biomass, easier contamination, and high cost of production. To overcome the challenge, engineered Chlamydomonas reinhardtii CC-400 with pyridoxal kinase gene (pdxY) has demonstrated in this study. The results indicated CC-400 with pdxY reached enhanced algal biomass in three different systems, including flask, Two-layer Photo-Reactor (TPR) and airlift Photo-Bioreactor (PBR). The genetic strain PY9 cultured with 1% CO 2 in the PBR showed a significant enhancement of biomass up to 1.442 g/L, a 2-times of that of the wild type. We also found the transcriptional levels of carbonic anhydrase (CA) dropped down in PY9 while higher levels of RuBisCo and pdxY occurred, thus the carbon dioxide assimilation under mixotrophic culture dramatically increased. We proofed that pdxY successfully mediated carbon dioxide utilization in CC-400., (Copyright © 2020. Published by Elsevier Ltd.)

Global warming is a surging issue that has provoked the demand of green process to mitigate carbon dioxide. In this context, RuBisCo-equipped Escherichia coli has first developed and evaluated the CO 2 -assimiliable capability based on the mass balance in three devices: Flask-based in CO 2 incubator (FIC), two-layered device (TLD) and CO 2 bubbling device (CBD) systematically. With the forced diffusion of 5% CO 2 in CBD, which confers an efficient attack of CO 2 to RuBisCo, the CO 2 assimilation increased from -5.03 to -2.63 g-CO 2 /g-DCW. Furthermore, boosted CO 2 assimilation ability was observed by co-expression of GroELS chaperone with 71% reduction on CO 2 release. By DNA sequencing and tandem MS/MS analysis, the toxicity of RuBisCo and PRK was identified to interfere the sugar metabolism and energy producing, while the cell morphology was changed and observed in RuBisCo-equipped E. coli. Our study provides a new perspective of higher CO 2 assimilation for sustainable to eco-friendly green bioprocess., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Lactic acid (LA) fermentation was conducted with suspended and immobilized cells of an isolated Lactobacillus plantarum 23 strain using various fermentation strategies. Glucose and an alternative, relatively inexpensive carbon source - the hydrolysate of microalga Chlorella vulgaris ESP-31, were used as the carbon source. Batch fermentation using immobilized cells of L. plantarum 23 could enhance LA titer and yield by 43% and 39%, respectively, when compared with the suspended culture. Fed-batch culture integrated with in situ LA removal via ion exchange raised LA productivity by 72% by overcoming product inhibition. The highest LA productivity from glucose with PVA immobilized cells was 14.22 g/L/h, achieved under continuous operation at 50% w/v loading of immobilized beads and hydraulic retention time (HRT) of 2 h. PVA immobilized L. plantarum 23 could also use microalgal hydrolysate as the renewable carbon source, and the highest LA productivity was 9.93 g/L/h under continuous fermentation at 4 h HRT., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Microalgae and cyanobacteria are easy to culture, with higher growth rates and photosynthetic efficiencies compared to terrestrial plants, and thus generating higher productivity. The concept of microalgal biorefinery is to assimilate carbon dioxide and convert it to chemical energy/value-added products, such as vitamins, carotenoids, fatty acids, proteins and nucleic acids, to be applied in bioenergy, health foods, aquaculture feed, pharmaceutical and medical fields. Therefore, microalgae are annotated as the third generation feedstock in bioenergy and biorefinery. In past decades, many studies thrived to improve the carbon sequestration efficiency as well as enhance value-added compounds from different algae, especially via genetic engineering, synthetic biology, metabolic design and regulation. From the traditional Agrobacterium-mediated transformation DNA to novel CRISPR (clustered regularly interspaced short palindromic repeats) technology applied in microalgae and cyanobacteria, this review has highlighted the genome editing technology for biorefinery that is a highly environmental friendly trend to sustainable and renewable development., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

In this study, productions of microalgal proteins were explored via a circular economy concept. First, production of proteins from Chlorella vulgaris FSP-E (CV) and Chlorella sorokiniana (CS) was optimized by using favorable cultivation conditions and strategies. The optimal CO 2 concentration for the growth of both microalgae was 5% (v/v), while the optimal nitrogen source for CV and CS were 12 mM of NaNO 3 and NH 4 Cl, respectively. Addition of 12 mg/L ammonium iron (III) citrate enhanced protein production. Next, semi-batch cultivation strategy was employed to achieve a protein production of 793.3 and 812.8 mg/L for CV and C S, representing a 4.86 and 2.77 fold increase, respectively, in protein productivity. The obtained microalgal proteins consist of 40% essential amino acids. The CV and CS proteins possess prebiotic activities as they enhanced the growth of Lactobacillus rhamnosus ZY by 48 and 74%, respectively, with a good antibacterial activity against predominant pathogens., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

A lutein-enriched mutant, Chlorella sorokiniana MB-1-M12 was grown mixotrophically for lutein production. The lutein production efficiency of the strain was enhanced via optimizing the operating strategies. The results show that using semi-continuous cultivation with a medium replacement ratio of 75% resulted in a higher lutein productivity and lutein concentration of 6.24 mg/L/d and 50.6 mg/L, respectively, which were markedly higher than those obtained from batch and fed-batch cultivation. Cultivation under simulated outdoor cultivation conditions (i.e., temperature of 35 °C/25 °C for a 12 h/12 h light/dark cycle) could achieve the highest lutein productivity and lutein concentration of 3.34 mg/L/d and 30.8 mg/L, respectively. Lutein production via outdoor cultivation of MB-1-M12 strain with a 60-L tubular photobioreactor was performed using semi-continuous operation. With a medium replacement ratio of 75%, a good lutein productivity (4.46 mg/L/d) and concentration (27.4 mg/L) was obtained, indicating the feasibility of producing lutein under outdoor cultivation of the microalgal strain., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

A heterotrophic mutant of Chlorella sorokiniana MB-1-M12 was evaluated for its ability to produce lutein using organic carbon and nitrogen sources and without light irradiation. In batch fermentation, the maximal lutein content (3.67 mg lutein/g biomass) and productivity (2.84 mg/L/d) could be obtained when cultivated in BG-11 medium with 7.5 g/L glucose, 0.75 g/L urea, pH 7.5 and a C/N ratio of 10. A novel two-stage cultivation strategy that integrates fed-batch and semi-batch operations was applied to enhance the lutein production performance. When growing MB-1-M12 strain in a 5L fermenter using the optimal operation strategies, the maximum biomass concentration, biomass productivity, lutein content and lutein productivity could reach 25 g/L, 4.88 mg/L/d, 5.88 mg/g and 16.2 mg/L/d, respectively. This high lutein productivity could significantly reduce the cultivation time and the associated costs, indicating the potential of using MB-1-M12 strain for heterotrophic lutein production in commercial scale., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In this study, CRISPRi (clustered regularly interspaced short palindromic repeats interference) was used for the first time to regulate expression of exogenously supplied rfp gene as a proof-of-concept, and endogenous PEPC1 gene as a proof-of-function in Chlamydomonas reinhardtii. The efficiency of 94% and stability of 7 generations via CRISPRi mediated gene regulation in C. reinhardtii have been demonstrated by RFP. Gene PEPC1 encoding proteins are essential for controlling the carbon flux that enters the TCA cycle and plays a crucial role in carbon partitioning of substrates in competition with lipid synthesis. All CrPEPC1 down-regulated strains have lower chlorophyll color, but higher biomass concentration and lipid accumulation rate. The present results revealed that CRISPRi based transcriptional silencing was applicable in C. reinhardtii and expanded the way to improve the yield, titer and productivity of microalgae-based products., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Shewanella xiamenensis (SXM) was found to produce nanoparticles (NPs) under aerobic condition. The oxidoreductase enzymatic activities including of catalase, manganese peroxidase, laccase, NADH dehydrogenase, flavin reductase, azoreductase and Fe reductase are first investigated. Catalase showed the greatest enzymatic activity among all oxidoreductases in SXM, which with strong activities in multiple substrates of ABTS, guaiacol and 2,6-DMP. The optimum temperature, pH, concentrations of H2O2 and 2,6-DMP for this enzyme were found to be 65 °C, pH 4.0, 128.7 mM and 10 mM, respectively. Finally, from the kinetic parameters and structure simulation of catalase, implied that SXM would potentially apply in bioremediation, microbe fuel cells (MFCs) and nano-biotechnology based on its distinguished enzymatic system., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

A new isolated Schizochytrium sp. LU310 from the mangrove forest of Wenzhou, China, was found as a high producing microalga of docosahexaenoic acid (DHA). In this study, the significant improvements for DHA fermentation by the batch mode in the baffled flasks (i.e. higher oxygen supply) were achieved. By applied the nitrogen-feeding strategy in 1000 mL baffled flasks, the biomass, DHA concentration and DHA productivity were increased by 110.4%, 117.9% and 110.4%, respectively. Moreover, DHA concentration of 21.06 g/L was obtained by feeding 15 g/L of glucose intermittently, which was an increase of 41.25% over that of the batch mode. Finally, an innovative strategy was carried out by intermittent feeding carbon and simultaneously feeding nitrogen. The maximum DHA concentration and DHA productivity in the fed-batch cultivation reached to 24.74 g/L and 241.5 mg/L/h, respectively., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

This is the first attempt to study the synergistic effect between Trichoderma reesei cellulases and the abundant agricultural tea waste in absorption of heavy metal Cr(VI) as well as its kinetic model development. The properties of tea waste were first analyzed by near infrared spectroscopy (NIR), particle size distribution (PSD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) examination with EDX for comparison between its original (UN-TW) and cellulase-hydrolyzed (TRCEL-TW) conditions. Then, an advanced kinetic model in the form of -d[Cr(VI)]/dt = A[H+](n)e(-Ea/RT) [Cr(VI)](m)(0), which can successfully predict the time-dependent Cr(VI) concentration of various pHs, initial Cr(VI) concentrations and temperatures was developed. The demonstrated synergistic effects of T. reesei cellulases on tea waste suggested that cellulosic material provides more accessibility area for absorption of heavy metal. This study also provides an alternative approach to remove toxic Cr(VI) from aqueous solutions and extend the utilization of agricultural tea waste., (Copyright © 2013. Published by Elsevier Ltd.)

As decolorized intermediates could play a role of electron-shuttling mediator to enhance the performance of dye decolorization and bioelectricity generation, this study selected model compounds with auxochromes (e.g., benzene-1,2-diol, 1,2-diaminobenzene) to explore how chemical structure(s) affected color removal and power producing capabilities in microbial fuel cells (MFCs). According to cyclic voltammetry, respiratory testing and MFC data, promising electron-shuttling capabilities of aforementioned compounds were revealed using Proteus hauseri ZMd44, Aeromonas sp. C78, Acinetobacter johnsonii NIUx72 bearing MFCs. These findings clearly indicated that chemical structure(s) of decolorized mediators directly affected characteristics of simultaneous reductive decolorization and bioelectricity generation in MFCs, suggesting feasible operation strategy of MFCs for industrial applications., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Four indigenous thermo-tolerant Desmodesmus sp. strains were examined for their ability to produce lutein. Among them, Desmodesmus sp. F51 was the best strain for this purpose. The medium composition, nitrate concentration and light intensity were manipulated to improve the phototrophic growth and lutein production of Desmodesmus sp. F51. It was found that a nitrogen-sufficient condition was required for lutein accumulation, while a high light intensity enhanced cell growth but caused a decrease in the lutein content. The best cell growth and lutein production occurred when the light intensity and initial nitrate concentration were 600 μmol/m(2)/s and 8.8 mM, respectively. The fed-batch cultivation strategy was shown to further improve lutein production. The highest lutein productivity (3.56±0.10 mg/L/d) and content (5.05±0.20 mg/g) were obtained when pulse-feeding of 2.2 mM nitrate was employed. This study demonstrated the potential of using Desmodesmus sp. F51 as a lutein producer in practical applications., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Dynamic synergistic effects in cellulosic bioconversion have been revealed between Trichoderma reesei cellulases and β-glucosidases (BGLs) from six Taiwanese fungi. A high level of synergy (8.9-fold) was observed with the addition of Chaetomella raphigera BGL to T. reesei cellulases. In addition, the C. raphigera BGL possessed the highest activity (V(max)/K(m)=46.6 U/mg mM) and lowest glucose inhibition (Ki=4.6mM) with the substrate 4-nitrophenyl β-d-glucopyranoside. For the natural cellobiose substrate, however, the previously isolated Aspergillus niger BGL Novo-188 had the highest V(max)/K(m) (0.72 U/mg mM) and lowest Ki (59.5mM). The demonstrated dynamic synergistic effects between some BGLs and the T. reesei cellulase system suggest that BGLs not only prevent the inhibition by cellobiose, but also enhance activities of endo- and exo-cellulases in cellulosic bioconversion. Comparisons of kinetic parameters and synergism analyses between BGLs and T. reesei cellulases can be used for further optimization of the cellulosic bioconversion process., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

This first-attempt study quantitatively explored interactive characteristics of bioelectricity generation and dye decolorization in air-cathode single-chamber microbial fuel cells (MFCs) using indigenous Proteus hauseri ZMd44. After approx. 15 cycles (30 days) acclimatization in dye-bearing cultures, P. hauseri could express its stable capability of simultaneous bioelectricity generation and color removal (SBP&CR) in MFCs. Evidently, appropriate acclimation strategy for formation of the electrochemically active anodic biofilm played a crucial role to enhance the performance of SBP&CR in MFCs. Gradually increased supplementations of C.I. reactive blue 160 resulted in progressively decreased decay rate of bioelectricity generation. That is, a dye decolorized in a faster rate would result in a lower capability for bioelectricity generation and vice versa. In addition, a reduced dye with less toxicity potency (e.g., 2-aminophenol) might work as a redox mediator of electron transport to anodic biofilm for bioelectricity generation in MFCs., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

A high yield of beta-glucosidase (EC 3.2.1.21) of 159.1 U/g-solid activity on 4-nitrophenyl beta-d-glucopyranoside (pNPG) was achieved by rice bran-based solid-state fermentation (SSF) of the recently characterized fungus Penicillium citrinum YS40-5. The enzyme was both thermophilic and acidophilic at the optimized temperature and pH of 70 degrees C and 5.0, respectively. Over 95% of the original beta-glucosidase activity was maintained after a prolonged storage at ambient temperature for 4 weeks. The kinetic parameters V(max), K(m) and K(I) were 85.93 U/mg, 1.2 mM and 17.59 mM with pNPG, and 72.49 U/mg, 32.17 mM and 8.29 mM with cellobiose, respectively. The protein band with beta-glucosidase activity was characterized by native PAGE followed by MUG-zymogram analysis, and its identity confirmed by nanoLC-MS/MS. A 3.43-fold synergistic effect by combining this beta-glucosidase with Trichoderma reesei cellulases was observed, indicating this enzyme could potentially be used for improving the efficiency of cellulosic bioconversion.