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Lipase from Pseudomonas sp. was entrapped by drop-wise addition of an aqueous mixture of alginate and the biocatalyst to hardening solution of CaCl2 for the purpose of palm olein hydrolysis. Effects ofimmobilization conditions including alginate concentration, CaCl2 concentration, enzyme concentration and bead size on immobilized yield, immobilized lipase activity and recovery of activity (specific activity ratio ofentrapped lipase to free lipase) were investigated. An increase in alginate concentration raised immobilized yield, but decreased immobilized lipase activity and recovery of activity. CaCl2 concentration in the testedrange of 50-200 mM had slight effects on immobilized yield, immobilized lipase activity and recovery of activity. In contrast to immobilized lipase activity, immobilized yield and recovery of activity decreased withincreasing enzyme concentration. With increasing bead size, immobilized lipase activity and recovery of activity decreased due to mass transfer resistance whereas immobilized yield was unchanged. The optimumcondition for lipase entrapment in alginate gel bead was alginate concentration at 2% (w/v), CaCl2 concentration at 100 mM, enzyme concentration at 30 U/ml and bead size at 2 mm. Under this entrapmentcondition, 8.11 U/ml of immobilized lipase was obtained with 95.2% of immobilized yield and 22.2% of recovery of activity.

Aims: Application of volatile organic compounds (VOCs) from Streptomyces salmonis PSRDC‐09 (VOCs PSRDC‐09) grown on sterile wheat seeds against chili anthracnose pathogen was investigated in vitro and in vivo. Methods and Results: Among 10 isolates of Colletotrichum species tested, Colletotrichum gloeosporioides PSU‐03 was selected as the most aggressive anthracnose pathogenic strain on chili fruit against VOCs produced by Streptomyces species. Among 11 isolates, the strain PSRDC‐09 exhibited the highest antifungal activity and was identified as S. salmonis PSRDC‐09. The antagonistic mechanism of the VOCs PSRDC‐09 on morphological of C. gloeosporioides PSU‐03, observed by scanning electron microscope (SEM), revealed the irregular distortions in the fungal hyphae. The effect of inoculum size and spore concentration of S. salmonis PSRDC‐09 prepared as a wheat seed inoculum on the suppression of C. gloeosporioides PSU‐03 was studied both in vitro and on chili fruit. The optimum inoculum size (45 g 0·31 l−1) and spore concentration (107 spores per ml) of the wheat seed culture of S. salmonis PSRDC‐09 exhibited the complete suppression (100% inhibition) on C. gloeosporioides PSU‐03. The optimum fumigation period of the VOCs PSRDC‐09 (45 g 1·38 l−1) was found to be 24 h. Based on gas chromatography‐mass spectrometry (GC‐MS) analysis, 14 major VOCs (produced by the strain PSRDC‐09) were detected and l‐linalool was the main volatile component. Conclusions: The results indicated that the VOCs from S. salmonis PSRDC‐09 could effectively control the chili anthracnose disease caused by C. gloeosporioides. Significance and Impact of the Study: These findings suggest that S. salmonis PSRDC‐09 may have the potential to become a promising biofumigant for biocontrol of chili anthracnose disease in the postharvest system. [ABSTRACT FROM AUTHOR]

Bioactive compounds derived from chitosan are exploited in various applications, and enzymatic hydrolysis of chitosan substrate using chitosanases is a promising approach to prepare these compounds. However, low yield and high cost of enzyme production still limit its use. The use of agricultural residues is an alternative to reduce the enzyme production costs. The present work aimed to use shrimp shell as a cheap substrate for the production of chitosanase, and to apply the obtained enzyme in producing antimicrobial compounds. The isolated Lentzea sp. strain OUR-I1 was able to use shrimp shell waste as a nutrient source and exhibited high chitosanase activity. Although shrimp shell powder (1.5%, w/v) could be used as the main carbon source in producing chitosanase, the addition of chitosan powder (0.05%, w/v) as an inducer substantially increased chitosanase activity. Other factors involved in the production of chitosanase were also optimised. Under these optimised conditions, the obtained amount of chitosanase increased by about 17-fold from 0.14 ± 0.006 to 2.4 ± 0.038 U/mL. Additionally, the partially purified chitosanase could effectively hydrolyse insoluble forms of chitosan into a hydrolysate mixture which in turn exhibited antimicrobial activities against a broad spectrum of food-pathogenic bacteria. The present work proposes a cost-efficient and environmentally friendly approach to produce chitosanase by a newly isolated bacterial strain, and demonstrates high potential of the obtained enzyme in the preparation of antimicrobial compounds. [ABSTRACT FROM AUTHOR]

A mathematical model for kefiran production by Lactobacillus kefiranofaciens was established, in which the effects of pH, substrate and product on cell growth, exopolysaccharide formation and substrate assimilation were considered. The model gave a good representation both of the formation of exopolysaccharides (which are not only attached to cells but also released into the medium) and of the time courses of the production of galactose and glucose in the medium (which are produced and consumed by the cells). Since pH and both lactose and lactic acid concentrations differently affected production and growth activity, the model included the effects of pH and the concentrations of lactose and lactic acid. Based on the mathematical model, an optimal pH profile for the maximum production of kefiran in batch culture was obtained. In this study, a simplified optimization method was developed, in which the optimal pH profile was determined at a particular final fermentation time. This was based on the principle that, at a certain time, switching from the maximum specific growth rate to the critical one (which yields the maximum specific production rate) results in maximum production. Maximum kefiran production was obtained, which was 20% higher than that obtained in the constant-pH control fermentation. A genetic algorithm (GA) was also applied to obtain the optimal pH profile; and it was found that practically the same solution was obtained using the GA. [ABSTRACT FROM AUTHOR]

Microalgae-fungal pellets were applied as novel dual-biosorbents for dye removal compared to fungal pellets. Both pellet types effectively removed anionic dyes better than cationic dyes, with the maximum adsorbing efficiency being nearly 100 % at a wide pH range of 3-8. The adsorption isotherms of anionic Congo Red dye and Coomassie brilliant blue R-250 dye using both pellet types and their biosorption kinetics were intensively studied. Noteworthy, the maximum adsorption capacity and affinity of microalgae-fungal pellets were much higher than those of fungal pellets. Both fungal pellets were also applied in the bioremediation of palm oil mill effluent (POME). The repeated treatment of POME by replacing pellets every 12 h enhanced the percent removal of color, phenolic compounds, and COD up to 90.97 ± 0.36 %, 70.71 ± 0.90 % and 56.55 ± 1.98 %, respectively. This study has demonstrated the promising potential for addressing dye removal and bioremediation of colored-industrial effluent in a sustainable and economically viable manner., 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.)

Aquaculture farming generates a significant amount of wastewater, which has prompted the development of creative bioprocesses to improve wastewater treatment and bioresource recovery. One promising method of achieving these aims is to directly recycle pollutants into microbe-rice bran complexes, which is an economical and efficient technique for wastewater treatment that uses synergetic interactions between algae and bacteria. This study explores novel bioaugmentation as a promising strategy for efficiently forming microbial-rice bran complexes in unsterilized aquaculture wastewater enriched with agricultural residues (molasses and rice bran). Results found that rice bran serves a dual role, acting as both an alternative nutrient source and a biomass support for microalgae and bacteria. Co-bioaugmentation, involving the addition of probiotic bacteria (Bacillus syntrophic consortia) and microalgae consortiums (Tetradesmus dimorphus and Chlorella sp.) to an existing microbial community, led to a remarkable 5-fold increase in microbial-rice bran complex yields compared to the non-bioaugmentation approach. This method provided the most compact biofloc structure (0.50 g/L) and a large particle diameter (404 μm). Co-bioaugmentation significantly boosts the synthesis of extracellular polymeric substances, comprising proteins at 6.5 g/L and polysaccharides at 0.28 g/L. Chlorophyta, comprising 80% of the total algal phylum, and Proteobacteria, comprising 51% of the total bacterial phylum, are emerging as dominant species. These microorganisms play a crucial role in waste and wastewater treatment, as well as in the formation of microbial-rice bran complexes that could serve as an alternative aquaculture feed. This approach prompted changes in both microbial community structure and nutrient cycling processes, as well as water quality. These findings provide valuable insights into the transformative effects of bioaugmentation on the development of microbial-rice bran complexes, offering potential applications in bioprocesses for waste and wastewater management., 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 Inc. All rights reserved.)

Microalgal biomass is gaining increasing attention to produce high-value co-products. This study proposes integrating Chlorella microalgal biomass into a zero-waste biorefining system, aiming to produce biodiesel and biofertilizer. It investigates optimal conditions for ultrasound-assisted deep eutectic solvent (DES) pretreatment and lipid recovery to enhance the extraction of lipids. Optimal DES pretreatment was identified as a 1.6:1 acetic acid-to-choline chloride molar ratio, 0.36 g biomass loading, and 2.50 min of pretreatment. Lipid recovery succeeded with a 10-minute extraction time and a 1:3 methanol-to-butanol volume ratio. These conditions yielded biodiesel-quality lipids at 139.52 mg/g microalgal biomass with superior fuel characteristics. The de-oiled microalgal biomass residue exhibited promise as a lettuce biofertilizer, enhancing photosynthetic pigments but potentially reducing yields by 40 %. The study also notes changes in rhizosphere microbial communities, indicating both stimulatory and inhibitory effects on beneficial microbes. This study has the potential to enhance sustainability in energy, agriculture, and the environment., 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.)

Microalgae growth-promoting bacteria (MGPB), both actinobacteria and non-actinobacteria, have received considerable attention recently because of their potential to develop microalgae-bacteria co-culture strategies for improved efficiency and sustainability of the water-energy-environment nexus. Owing to their diverse metabolic pathways and ability to adapt to diverse conditions, microalgal-MGPB co-cultures could be promising biological systems under uncertain environmental and nutrient conditions. This review proposes the recent updates and progress on MGPB for microalgae cultivation through co-culture strategies. Firstly, potential MGPB strains for microalgae cultivation are introduced. Following, microalgal-MGPB interaction mechanisms and applications of their co-cultures for biomass production and wastewater treatment are reviewed. Moreover, state-of-the-art studies on synthetic biology and metabolic network analysis, along with the challenges and prospects of opting these approaches for microalgal-MGPB co-cultures are presented. It is anticipated that these strategies may significantly improve the sustainability of microalgal-MGPB co-cultures for wastewater treatment, biomass valorization, and bioproducts synthesis in a circular bioeconomy paradigm., 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 GmbH. All rights reserved.)

Food wastes have a large number of functional ingredients that have potential for valorization. Melon peels are increasingly produced as waste in food industries in Thailand. This study aimed to optimize pectin extraction conditions from melon peel for its prebiotic potential. Optimization was conducted using a response surface methodology and Box-Behnken experimental design. An analysis of variance indicated a significant interaction between the extraction conditions on extraction yield and degree of esterification (DE). These include pH and solvent-to-sample ratio. The conditions for the extraction of pectin with low DE (LDP), medium DE (MDP) and high DE (HDP) were optimized. Pectin hydrolysate from LDP, MDP and HDP was prepared by enzymatic hydrolysis into LPEH, MPEH and HPEH, respectively. LDP, MDP, HDP, LPEH, MPEH and HPEH were compared for their efficiency in terms of the growth of three probiotic strains, namely Lactobacillus plantarum TISTR 877, Lactobacillus casei TISTR 390 and Enterococcus faecium TISTR 1027. Among the samples tested, HPEH showed the highest ability as a carbon source to promote the growth and prebiotic activity score for these three probiotic strains. This study suggests that melon peel waste from agro-industry can be a novel source for prebiotic production.

Bacillus sp. TL7-3 has potential as a dietary supplement to promote human and animal health. It produces spores that can survive in harsh environments. Thus, when supplemented with nutrients, these spores can withstand the acidic pH of the stomach and resume vegetative development in the gut when exposed to growth-promoting conditions. Spores are formed as a cellular defense mechanism when a culture experiences stress and process optimization to achieve high spore production in a typical batch process remains challenging. Existing literature on the manipulation of gene expression and enzyme activity during batch cultivation is limited. Studies on the growth patterns, morphological changes, and relevant gene expression have aided in enhancing spore production. The present study used the response surface methodology for medium optimization. The model suggested that yeast extract and NH 4 Cl were significant factors controlling spore production. A comparison between the high weight ratio of carbon and nitrogen (C:N) substrates (8.57:1) in the optimized and basal media (0.52:1) showed an 8.76-fold increase in the final spore concentration. The expression of major genes, including codY , spo0A , kinA , and spo0F , involved in the sporulation was compared when cultivating Bacillus sp. TL7-3 in media with varying C:N ratios. At high C:N ratios, spo0A , kinA , and spo0F were upregulated, whereas codY was downregulated. This led to decreased guanylate kinase activity, resulting in a low guanosine triphosphate concentration and inactivation of CodY, thereby reducing the repression of spo0A and CodY-repressed genes and stimulating sporulation., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Nuttha Thongchul reports financial support was provided by 10.13039/501100004704National Research Council of Thailand. Nuttha Thongchul reports financial support was provided by 10.13039/501100004192National Science and Technology Development Agency. Suttichai Assabumrungrat reports financial support was provided by Research Chair Professor Grant. Sitanan Thitiprasert reports financial support was provided by Fundamental Research Fund. Benjamas Chiersilp reports financial support was provided by Thailand Research Fund. Phetcharat Jaiaue reports financial support was provided by Development and Promotion of Science and Technology Talents Scholarship Program. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

The conversion of renewable biomass feedstock into value-added products via bioprocessing platforms has become attractive because of environmental and health concerns. Process performance and cost competitiveness are major factors in the bioprocess design to produce desirable products from biomass feedstock. Proper pretreatment allows delignification and hemicellulose removal from the liquid fraction, allowing cellulose to be readily hydrolyzed to monomeric sugars. Several industrial products are produced via sugar fermentation using either naturally isolated or genetically modified microbes. Microbial platforms play an important role in the synthesis of several products, including drop-in chemicals, as-in products, and novel compounds. The key elements in developing a fermentation platform are medium formulation, sterilization, and active cells for inoculation. Downstream bioproduct recovery may seem like a straightforward chemical process, but is more complex, wherein cost competitiveness versus recovery performance becomes a challenge. This review summarizes the prospects for utilizing renewable biomass for bioprocessing., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests. Nuttha Thongchul reports financial support was provided by National Science and Technology Development Agency. Nuttha Thongchul reports financial support was provided by National Research Council. Panwana Khunnonkwao reports financial support was provided by C2F, Chulalongkorn University. Sitanan Thitiprasert reports financial support was provided by Fundamental Research Grant. Phetcharat Jaiaue reports financial support was provided by Development and Promotion of Science and Technology Talents. The authors declare no conflict of interest. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

This study aimed to increase the value of brewers' spent grain (BSG) by using it as feedstock to produce lignocellulolytic enzymes and lactic acid (LA). Twenty-two fungal strains were screened for lignocellulolytic enzyme production from BSG. Among them, Trichoderma sp. showed the highest cellulase activity (35.84 ± 0.27 U/g-BSG) and considerably high activities of xylanase (599.61 ± 23.09 U/g-BSG) and β-glucosidase (16.97 ± 0.77 U/g-BSG) under successive solid-state and submerged fermentation. The processes were successfully scaled up in a bioreactor. The enzyme cocktail was recovered and characterized. The maximum cellulase and xylanase activities were found at pH 5.0 and 50 °C, and the activities were highly stable at pH 4-8 and 30-50 °C. The enzyme cocktail was applied in simultaneous saccharification and fermentation of acid-pretreated BSG for LA production. The maximum LA obtained was 59.3 ± 1.0 g/L. This study has shown the efficient biovalorization of BSG, and this approach may also be applicable to other agro-industrial wastes., 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.)

Green biorefinery process was conducted to extract α-chitin and high-value co-products from shrimp shell waste through microbial fermentation using mature coconut water (MCW) as a sole nutrient source. Symbiotic co-lactic acid fermentation (Co-LAF) by Lactobacillus plantarum and Streptococcus thermophilus produced higher levels of lactic acid (LA) and protease activity than their mono-cultures, which led to greater demineralization (DM) and deproteinization (DP) of shrimp shell powder (SSP). After optimizing Co-LAF through Response Surface Methodology and successive fermentation by an acid-active proteolytic fungus Rhizopus oligosporus, the highest DM of 94.0 ± 0.91 % and DP of 86.7 ± 0.1 % were achieved. Based on FT-IR, XRD, and SEM analysis, the bio-extracted chitin had similar structural characteristics to commercial α-chitin but with better quality. These strategies not only contribute to environmentally-friendly and cost-effective extraction of α-chitin (303 ± 18 mg/g-SSP), but also co-produce LA (57.18 ± 0.89 g/L), acid protease (4.33 ± 0.5 U/mL), bio-calcium (277 ± 12 mg-CaSO 4 /g-SSP), protein hydrolysate (268 ± 5 mg/g-SSP), and pigments (28.78 ± 1.56 µg/g-SSP)., 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.)

Microalgae are promising organisms that are rapidly gaining much attention due to their numerous advantages and applications, especially in biorefineries for various bioenergy and biochemicals. This review focuses on the microalgae contributions to Bio-Circular-Green (BCG) economy, in which zero-waste approaches for sustainable production and biorefineries of microalgal biomass are introduced and their possible integration is discussed. Firstly, overviews of wastewater upcycling and greenhouse gas capture by microalgae are given. Then, a variety of valuable products from microalgal biomass, e.g., pigments, vitamins, proteins/peptides, carbohydrates, lipids, polyunsaturated fatty acids, and exopolysaccharides, are summarized to emphasize their biorefinery potential. Techno-economic and environmental analyses have been used to evaluate sustainability of microalgal biomass production systems. Finally, key issues, future perspectives, and challenges for zero-waste microalgal biorefineries, e.g., cost-effective techniques and innovative integrations with other viable processes, are discussed. These strategies not only make microalgae-based industries commercially feasible and sustainable but also reduce environmental impacts., 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.)

This study pursued the goal of creating value-added co-products through an environmentally friendly biorefinery approach, employing ultrasonically assisted deep eutectic solvent (DES)-pretreated Chlorella biomass. The primary focus was on generating enriched biodiesel feedstock with exceptional fuel properties and developing hydroponic biofertilizer. The results demonstrated the effectiveness of a two-step process involving a 5-minute ultrasound-assisted DES pretreatment followed by ultrasound-assisted solvent extraction, which efficiently extracted lipids from Chlorella biomass, yielding biodiesel-quality lipids with good cetane number (59.42) and high heating value (40.11 MJ/kg). Notably, this two-step approach (78.04 mg-lipid/g-microalgal biomass) led to a significant 2.10-fold increase in lipid extraction compared to a one-step process (37.15 mg-lipid/g-microalgal biomass) that combined ultrasound-assisted DES pretreatment and solvent extraction. Importantly, the aqueous extract derived from lipid-extracted microalgal biomass residues (LMBRs) showed promise as a component in hydroponic biofertilizer production, supporting lettuce growth in hydroponic deep water culture system. Consequently, microalgae biorefinery co-products hold tremendous potential in enhancing the profitability and sustainability of interconnected sectors, encompassing renewable energy, agriculture, and the environment., 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 The Authors. Published by Elsevier B.V. All rights reserved.)

The economical bio-butanol-based fermentation process is mainly limited by the high price of first-generation biomass, which is an intensive cost for the pretreatment of second-generation biomass. As third-generation biomass, marine macroalgae could be potentially advantageous for conversion to clean and renewable bio-butanol through acetone-butanol-ethanol (ABE) fermentation. In this study, butanol production from three macroalgae species (Gracilaria tenuistipitata, Ulva intestinalis, and Rhizoclonium sp.) by Clostridium beijerinckii ATCC 10132 was assessed comparatively. The enriched C beijerinckii ATCC 10132 inoculum produced a high butanol concentration of 14.07 g L -1 using 60 g L -1 of glucose. Among the three marine seaweed species, G. tenuistipitata exhibited the highest potential for butanol production (1.38 g L -1 ). Under the 16 conditions designed using the Taguchi method for low-temperature hydrothermal pretreatment (HTP) of G. tenuistipitata, the maximum reducing sugar yield rate of 57.6% and ABE yield of 19.87% were achieved at a solid to liquid (S/L) ratio of 120, temperature of 110°C, and holding time of 10 min (Severity factor, R 0 1.29). In addition, pretreated G. tenuistipitata could be converted to 3.1 g L -1 of butanol using low-HTP at an S/L ratio of 50 g L -1 , temperature of 80°C (R 0 0.11), and holding time of 5 min., (© 2023 Wiley-VCH GmbH.)

Yeast-bacterium interaction has recently been investigated to benefit the production of cell-bound lipases (CBLs). Staphylococcus hominis AUP19 supported the growth of Magnusiomyces spicifer AW2 in a palm oil mill effluent (POME) medium to produce CBLs through a bioremediation approach, including oil and grease (O&G) and chemical oxygen demand (COD) removals. This research used the yeast-bacterium co-culture to optimize CBLs and cell biomass (CBM) productions through bioremediation using the statistical Plackett-Burman design and response surface methodology-central composite design. The CBLs were finally applied in biodiesel synthesis. The CBM of 13.8 g/L with CBLs activity at 3391 U/L was achieved after incubation at room temperature (RT, 30 ± 2 °C) for 140 h in 50% POME medium, pH 7.0, containing 1.23% (w/v) ammonium sulfate. Bacterium promoted yeast growth to achieve bioremediation with 87.9% O&G removal and 84.5% COD removal. Time course study showed that the CBLs activity was highest at 24 h cultivation (4103 U/L) and retained 80% and 60% of activities at 4 °C and RT after 5 weeks of storage. The CBLs application successfully yielded 77.3% biodiesel from oleic acid (esterification) and 86.4% biodiesel from palm oil (transesterification) within 72 h in solvent-free systems. This study highlights that yeast-bacterium co-culture and POME should receive more attention for potential low-cost CBLs production through bioremediation, i.e., O&G and COD removals, while the CBLs as biocatalysts are promising for significant contribution to an effective strategy for economic green biodiesel production., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Palm empty fruit bunches (EFB) were valorized into fungal lipids by oleaginous fungus Aspergillus tubingensis TSIP9 under solid-state fermentation (SSF) and submerged fermentation (SmF). An integrated SSF-SmF process increased lipid production from 116.2 ± 0.1 mg/g-EFB under SSF and 60.1 ± 0.2 under SmF up to 124.9 ± 0.5 mg/g-EFB, possibly due to the combined benefits of dispersed mycelia forming during SSF and better mass transfer during SmF. As A. tubingensis lacks sufficient β-glucosidase, it was co-cultured with high β-glucosidase-producing Trichoderma reesei QM 9414. The co-cultures improved overall lipid yields likely due to synergistic interaction of the two fungi. After inoculum size was optimized and the co-cultures were performed in bioreactors, the lipid yield was increased up to 205.1 ± 1.1 mg/g-EFB. The fatty acid composition of fungal lipids indicated their potential use as biodiesel feedstocks. The fungal fermentation of EFB also provided cellulose pulp residues. These strategies could be practical options for low-cost biovalorization of biomass wastes., 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.)

This study involves the isolation of succinic acid (SA)-producing microorganisms from different samples, including the rumen, sludge, soil, and wastewater. For primary screening, 29 isolates exhibited a zone of clearance around the colony, indicating acid production. For secondary screening using thin-layer chromatography, only two isolates symbolized SA production according to their R f values. These two isolates were further identified as Bacillus velezensis and Enterococcus gallinarum by phylogenetic analysis using the neighbor-joining method. The high SA concentrations of 50.2 and 66.9 g/L were produced by B. velezensis and E. gallinarum with an SA yield of 0.836 and 1.12 g/g glucose, respectively. The high SA concentration from these newly isolated strains was achieved with a low formation of unwanted acids compared with those from Actinobacillus succinogenes ATCC 55618. Moreover, E. gallinarum was cultured in palm oil mill wastewater (POMW) and molasses, which were cheap substrates. The high SA production of 73.9 g/L with low other acids (the ratio of SA to total acids = 0.917) was achieved using POMW and molasses (80:20) as substrates., (© 2022 International Union of Biochemistry and Molecular Biology, Inc.)

Eco-friendly natural pigment demand has ever-increasing popularity due to health and environmental concerns. In this context, the aim of this study was to evaluate the feasibility use of Saba banana peel as low-cost fermentable substrate for the production of pigments, xylanase and cellulase enzymes by Monascus purpureus. Among the strains tested, M. purpureus TISTR 3385 produced pigments better and had higher enzyme activities. Under the optimal pigment-producing conditions at the initial moisture content of 40% and initial pH of 6.0, the pigments comprising yellow, orange, and red produced by the fungi were achieved in the range of 0.40-0.93 UA/g/day. The maximum xylanase and cellulase activities of 8.92 ± 0.46 U/g and 4.72 ± 0.04 U/g were also obtained, respectively. More importantly, solid-state fermentation of non-sterile peel could be achieved without sacrificing the production of the pigments and both enzymes. These indicated the potential use of the peel as fermentable feedstock for pigment production by the fungi and an environmental-friendly approach for sustainable waste management and industrial pigment and enzyme application., (© 2022. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)

Oleaginous microalga Scenedesmus sp. SPP was rapidly immobilized in oleaginous fungal pellets by their opposite-surface-charges. Microalgae-fungal (MF) pellets were more effective in bioremediation of non-sterile secondary effluent than mono-culture. The optimal hydraulic retention time for dual bioremediation in semi-continuous mode was 72 h. The MF pellets coated with 0.4 %-chitosan improved removal efficiencies of COD, total nitrogen (TN), and total phosphorus (TP) up to 96.2±0.0 %, 88.2±2.8 % and 71.5±0.7 %, respectively, likely because of better cell retention and more nutrient adsorption and assimilation. Dual bioremediation by coated MF pellets was also successfully scaled up in 30-L bubble-column photobioreactors with improved COD, TN, and TP removal efficiencies of 98.5±0.0 %, 90.2±0.0 % and 79.5±2.1 %, respectively. This system also effectively removed CO 2 from simulated flue gas at 71.2±0.4 % and produced biomass with high lipid content. These results highlight the effectiveness of bio-immobilization by fungal pellets; chitosan coating; and their practical applications in bioremediation and CO 2 sequestration., 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.)

This study performs an integrated evaluation of the formation and distribution of algal-bacterial bioflocs in aquaculture wastewater supplemented with agricultural waste, together with an assessment of their behavior in the microbial community and of the water quality of the system in which a new bioaugmentation strategy was applied. Results indicated that the dual bioaugmentation strategy via the consortium addition of bacteria and microalgae had the highest formation performance, providing the most compact biofloc structure (0.59 g/L), excellent settleability (71.91%), and a large particle diameter (4.25 mm). The fed-batch supplementation of molasses and rice bran, in terms of changes in the values of COD, NH 4 + , NO 3 - , and PO 4 3- , stimulated the formation of biofloc through algal-bacterial bioflocs and microbe-rice bran complexes within a well-established microbial community. These findings provide new insight into the influence of bioaugmentation on the formation of an innovative algal-bacterial biofloc., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

High-strength waste activated sludge (WAS) and greasy sludge (GS) were largely generated from canned tuna processing. This study reports the performance of the two-stage anaerobic process for co-digesting WAS and GS. Various WAS:GS mixing ratios of 0:100, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10, and 100:00 (volatile solids (VS) basis) were investigated in batch acidogenic stage at ambient (30 °C ± 3 °C), 55 °C, and 60 °C temperatures. Subsequently, the effluents from the first stage were used to produce methane in the second methanogenic stage at an ambient temperature. The highest methane yield of 609 mL CH 4 /g-VS added was achieved using acidogenic effluents generated from a WAS:GS mixing ratio of 40:60 at an ambient temperature. The first-order kinetic constants (k) for the first (k 1 ) and second (k 2 ) stages were subsequently estimated to be 0.457 d -1 and 0.139 d -1 , respectively. The obtained k constants were further used to predict the hydraulic retention time (HRT) for the two continuously stirred tank reactors (CSTR) in series. Consequently, the calculated 4-day HRT and 20-day HRT for 50-L CSTR 1 and 250-L CSTR 2 , respectively, were used to operate the continuous two-stage process at an ambient temperature by feeding with a 40:60-WAS:GS mixing ratio. A satisfactory methane yield of 470-mL CH 4 /g-VS along with 75% chemical oxygen demand (COD) removal was generated. Furthermore, the predicted methane yield of 450-mL CH 4 /g-VS obtained from the simple kinetic CSTR model resembled the experimental yield with 96% accuracy. The obtained experimental results demonstrate that WAS and GS co-digestion could be successfully accomplished using a practical two-stage anaerobic process operated at an ambient temperature., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Waste-activated sludge (WAS) and greasy sludge (GS) discharged from the canned tuna industry are considerably characterized as harsh organic wastes to be individually treated by using traditional anaerobic digestion. This study was attempted to anaerobically co-digest WAS and GS in continuous pilot scale two-stage process, comprising the first 50 L continuous stir tank reactor (CSTR 1 ) and the second 250 L continuous stir tank reactor (CSTR 2 ). The two-stage co-digesting operation of dewatered WAS:GS ratio of 0.4:1 (g-VS) at ambient temperature with the organic loading rate (OLR) of 12.6 ± 0.75 g-VS/L·d and 2.26 ± 0.13 g-VS/L·d, corresponding to 3-day and 17-day hydraulic retention time (HRT) for the first and second stage, respectively generated highest methane production rate of 957 ± 86 mL-CH 4 /L·d, corresponding to methane yield of 423.4 ± 36 mL-CH 4 /g-VS. Organic removal efficiency obtained was around 67.5% on COD basis. The microbial diversity was depended on the process's activity. Bacteria were mostly detected in the CSTR 1 , dominating with the phylum Firmicutes and Proteobacteria, whereas genus Methanosaeta archaea were found dominantly in the CSTR 2 . The economic analysis of process shows payback period (PBP), internal rate of return (IRR), and net present value (NPV) of 3 years, 30%, and 250,177 USD, respectively. This study demonstrated the potential approach to applying the two-stage anaerobic co-digestion process to stabilize both WAS and GS along with generating valuable bioenergy carriers., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The potential of oil palm ash (OPA) to enhance H 2 S and CO 2 removal from biogas by scrubbing with maturation pond effluent (MPE), and further the treatment of biogas scrubber effluent (BSE) by Ceratophyllum demersum L. (hornwort) cultivation were investigated in this study. The results show that OPA + MPE solution with pH 9.3 and alkalinity 7525 mg CaCO 3 /L was obtained with 0.7 kg/L OPA loading. A pilot scale scrubber was used to study the effects of absorbent flow rates of 60-210 L/h on upgrading to 300 L/h field biogas stream. At 210 L/h, the CO 2 removal efficiencies were 33% and 53% for MPE and OPA + MPE, respectively. To approach 100% H 2 S removal efficiency, the minimum flow rates were 120 L/h for MPE and 90 L/h for OPA + MPE. 50-150 g wet weight of hornwort in 30 L diluted POME were loaded to investigate appropriate initial hornwort loading level for hornwort cultivation. The highest specific growth rate of 0.045 day -1 with biomass production of 3.8 g/day were obtained with a 50 g initial loading. Among the wastewaters (MPE, OPA + MPE, and BSE) treatment using hornwort cultivation, the highest 0.035 day -1 specific growth rate and 2.6 g/day biomass production of hornwort were obtained in diluted BSE cultivation, and in 3 weeks of cultivation. COD, nitrate, phosphate, and alkalinity decreased by 76%, 76%, 55%, and 5%, respectively. The Eco-Efficiency concept for palm oil mill waste utilization proposed in this study has a high potential for enhanced biogas upgrading by using OPA + MPE, and hornwort is a good candidate for BSE post-treatment integrated with biomass production., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Botrytis cinerea is an economically important disease on numerous vegetables including tomato. From our previous studies, a spore suspension of Streptomyces philanthi RL-1-178 and RM-1-138 and Streptomyces mycarofaciens SS-2-243 showed strong inhibition against B. cinerea. In this study, the efficacy of their antifungal metabolites against B. cinerea was investigated after enhancing the production through the optimum culture medium and environmental conditions (temperature, light/dark cycle). In vitro studies indicated that glucose yeast-malt (GYM) agar and incubation at 28°C were optimal for growth and mass spore production of all three Streptomyces strains. Moreover, light/dark conditions had a positive effect on the growth and spore production of S. philanthi RM-1-138 and RL-1-178 but not on S. mycarofaciens SS-2-243. Both strains of S. philanthi possessed an antifungal activity against B. cinerea (100% inhibition) while S. mycarofaciens showed different results on PDA (83% inhibition) and GYM (88% inhibition) at the optimum incubation temperature at 21°C. The antifungal compounds from S. philanthi RM-1-138 exhibited the highest protection efficacy against B. cinerea on tomato leaves (82.89% and 0.33 cm 2 lesion areas symptoms). The antifungal compounds RM-1-138, identified by GC-MS, were greatly altered based on components concentration under various temperatures and light/dark conditions. The anti-B. cinerea of S. philanthi RM-1-138 was established at a higher level in several metabolic compounds in the dark condition (11 and 32 antifungal compounds after incubation at 21°C and 28°C, respectively) than in the light condition (11 and 19 antifungal compounds after incubation at 21°C and 28°C, respectively). At 21°C, the dominant component was acetic acid (67.41% and 68.77% in light and dark conditions, respectively) while at 28°C, benzeneacetamide (43.58% in light) and propanamide (20.68% in the dark) were dominant. The results clearly demonstrated the significant influence of environmental factors on the production of antifungal metabolites of Streptomyces spp., (© 2022 Wiley-VCH GmbH.)

This work attempted the conversion of crude glycerol to lipid and lipase by Yarrowia lipolytica and the direct transesterification of wet yeast by its lipase into biodiesel via response surface methodology to enhance the cost-effectiveness of biodiesel production from the lipids. The yeast grew better and accumulated a high amount of lipids on the waste combined with fish waste hydrolysate, but only exhibited high lipase activity on the waste supplemented with surfactants (i.e., gum Arabic, Tween 20, Tween 80). However, the combination of both wastes and Tween 80 further improved growth, lipid productivity, and lipase activity. More importantly, lipase-direct transesterification under optimal conditions (wet cell concentration of 17.97 mg-DCW, methanol loading of 8.21 µL, and hexane loading of 10.26 µL) followed by acid-catalyst transesterification (0.4 M H 2 SO 4 ), offered high FAME yields (>90%), showing the efficiency of the process when applied for the industrialization of biodiesel production from microbial lipids., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Chitin extraction from shrimp shell powder (SSP) using protease-producing microbes is an attractive approach for valorizing shrimp shell waste because it is simple and environmentally friendly. In this study, the protease production and chitin extraction from SSP by Bacillus cereus HMRSC30 were simultaneously optimized using statistical approaches. As a result, fermentation in medium composed of 30 g/L SSP, 0.2 g/L MgSO 4 · 7H 2 O, 3 g/L (NH 4 ) 2 SO 4 , 0.5 g/L K 2 HPO 4 , and 1.5 g/L KH 2 PO 4 (pH 6.5) for 7 days maximized protease production (197.75 ± 0.33 U/mL) to approximately 1.64-fold compared to unoptimized condition (126.8 ± 0.047 U/mL). This level of enzyme production was enough to achieve 97.42 ± 0.28% deproteinization (DP) but low demineralization (DM) of 53.76 ± 0.21%. The high DM of 90% could be easily accomplished with the post-treatment using 0.4 M HCl and acetic acid. In addition, the study evaluated the possible roadmap to maximize the value of generated products and obtain additional profits from this microbial process. The observation showed the possibility of serving crude chitin as a bio-adsorbent with the highest removal capacity against Coomassie brilliant blue (97.99%), followed by methylene blue (74.42%). The recovered protease exhibited the function to remove egg yolk stain, indicating its potential for use as a detergent in de-staining. The results corroborated the benefits of microbial fermentation by B. cereus HMRSC30 as green process for comprehensive utilization of shrimp shell waste as well as minimizing waste generation along the established process., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Aims: This study aimed to use palm oil mill effluent (POME) as a renewable resource for the production of antifungal compounds by Streptomyces philanthi RM-1-138 against Ganoderma boninense, Ceratocystis paradoxa and Curvularia oryzae., Methods and Results: The efficacy of antifungal compounds RM-1-138 against the three strains of fungal oil palm pathogen was evaluated both in vitro and on oil palm leaf segments. In vitro studies using confrontation tests on glucose yeast-malt extract (GYM) agar plates indicated that the strain RM-1-138 inhibited the growth of all three fungal pathogenic strains. The antifungal compounds produced in the GYM medium exhibited significantly higher inhibition (79%-100%) against the three fungal pathogens than using the diluted POME (50%) medium (80%-83% inhibition). The optimum condition for the production of antifungal compounds from the strain RM-1-138 was as following: POME of 47,966 mg L -1 chemical oxygen demand (COD), the initial pH at 7.0 and supplemented with yeast extract (0.4%). Meanwhile, severe morphological and internal abnormalities in C. oryzae hyphae were observed under a scanning electron microscope and transmission electron microscope. In vivo experiment on oil palm leaf segments indicated that the efficacy of the antifungal compounds RM-1-138 (DSI = 1.3) were not significantly difference in the suppression of Curvularia leaf spot compared with the two commercial chemical fungicides of mancozeb ® (DSI = 1.0) and tetraconazole ® (DSI = 1.3)., Conclusions: Antifungal compounds produced by S. philanthi RM-1-138 grown in POME have the potential to inhibit fungal pathogens., Significance and Impact of the Study: The POME (about 47 mg L -1 COD) with the initial pH of 7.0 and supplementation of 0.4% nitrogen could be used as a culture medium for the growth and production of antifungal compounds of S. philanthi RL-1-138. In addition, the antifungal compound RM-1-138 could suppress the three strains of oil palm fungal pathogen tested on oil palm leaf segment., (© 2021 The Society for Applied Microbiology.)

This study aimed to develop efficient microbial fuel cells (MFCs) for integrated bioelectricity, biodiesel feedstock production and wastewater treatment. Among wastewaters tested, MFC fed with anaerobic digester effluent from rubber industry gave the maximum power density (55.43 ± 1.08 W/m 3 ) and simultaneously removed COD, nitrogen and phosphorus (by 72.4 ± 0.9%, 40.5 ± 0.8% and 24.4 ± 1.5%, respectively). 16S rRNA gene analysis revealed that dominant microbial communities were: Firmicutes (43.68%), Bacteroidetes (25.41%) and Chloroflexi (15.02%), which mostly contributed to bioelectricity generation. After optimizing organic loading rate, photosynthetic oleaginous microalgae were applied in cathodic chamber in order to increase oxygen availability, secondarily treat anodic chamber effluent and produce lipids as biodiesel feedstocks. Four MFCs with photosynthetic-cathodic chamber connected in vertical cascade could improve power density up to 116.9 ± 15.5 W/m 3 , sequentially treat wastewater, and also produce microalgal biomass (465 ± 10 g/m 3 ) with high lipid content (38.17 ± 0.01%). These strategies may greatly contribute to sustainable development of integrated bioenergy generation and environment., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Diatoms, as single cell eukaryotic microalgae, are rich sources of lipids, which have either beneficial or detrimental effects on the prevention and treatment of many diseases. Gas chromatography-mass spectrometry (GC-MS) identified diatom lipids with high levels of essential fatty acids (EFAs), especially polyunsaturated FAs (PUFAs) containing both omega-3 and omega-6. Nutritional values of FAs indicated possible applications in the pharmaceutical, nutraceutical, and functional food industries. Diatom FAs showed antioxidative potential on harmful radicals by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) scavenging, with high inhibition of the angiotensin-converting enzyme (ACE) that causes cardiovascular disease (CVD) and hypertension. A computational molecular docking simulation confirmed the inhibition mechanisms of FAs on ACE, with comparable levels of binding free energy to chemically synthesized ACE drugs. Findings suggested that diatom lipids showed potential for use as alternative ACE inhibitors or food supplement for CVD prevention.

Fungal xylanase was produced from lignocellulosic palm wastes through combined solid-state fermentation (SSF) and submerged fermentation (SmF) by Aspergillus tubingensis TSIP9 in a helical-impeller equipped bioreactor. The combined SSF-SmF promoted the xylanase production by 15 and 70% higher than SSF and SmF, respectively. Sequential purification yielded 7.4-fold purified xylanase with 9.07% recovery. The maximum activities of crude and purified xylanase were observed at the same pH of 5.0 and the same temperature of 50 °C while purified xylanase is more active and highly stable at a wider pH range of 3-8 and temperature of 30-60 °C. The half-life of purified xylanase at various temperatures was also much improved by 2-8 folds compared to crude xylanase. Michaelis-Menten constants, V max and K m , for purified xylanase are 2,602.8 U/mg and 32.4 mg/mL, respectively. Purified xylanase activity was most enhanced with Ca 2+ followed by Zn 2+ and Fe 2+ at 10 mM while significantly inhibited by Co 2+ , Cu 2+ , Pb 2+ , and Ag + . This study has shown the effectiveness of combined SSF-SmF for xylanase production and superior properties of purified xylanase for industrial processes.

Background: High quality RNA is required for the molecular study. Sample preparation of the spore-forming, Gram-positive bacteria like Bacillus sp., remains challenging although several methods have been proposed. Those techniques were simply developed using cell samples at certain growth stages despite some molecular studies like transcriptomic analyses require RNA samples from different physiological stages., Methods and Results: We developed the rapid, simple yet effective cell-lysis technique with limit use of harsh reagents by modifying the kit-based protocols. Appropriate lysozyme loading (20 mg/mL), incubation time (30 min), and temperature (37 °C) enabled cell lysis and enhanced RNA extraction from both vegetative cells and endospores of Bacillus subtilis TL7-3. High RNA Integrity Numbers and ratios of A 260 /A 280 and A 260 /A 230 of all RNA products collected during the batch cultivation confirmed that invert mixing with absolute ethanol prevented RNA damage during protein denaturation. With the process modification of the major steps in cell lysis and RNA extraction compared with the kit-based protocols that are typically used in laboratory work, interestingly, our modified protocol, simple-yet-effective, yielded higher concentration, purity, and integrity of RNA products from all cell samples collected at different physiological stages. While the kit-based protocols either failed to provide high RNA concentration or RNA purity and integrity for all cell samples particularly during the late-log, stationary, or sporulation., Conclusions: Therefore, we can claim the significance of this modified protocol to be applicable for RNA extraction to those spore-forming Gram-positive bacteria not limited to B. subtilis growing at varied physiological stages., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

The petroleum-based plastics, high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polypropylene (PP), and the biodegradable plastic, polylactide (PLA) were processed by thermal and catalytic pyrolysis to investigate their suitability as feedstock for chemical recycling. The influence of pyrolysis temperature (400-600 °C) and catalyst (zeolite, spent FCC, and MgO catalyst) on the pyrolysis liquid composition and yield was studied. The studied petroleum-based plastics had similar decomposition temperature ranges but produced their highest pyrolysis yields at different temperatures. Pyrolysis liquids from thermal degradation of HDPE and LDPE consisted high yield of waxes but those of PP and PLA consisted of both waxes and liquid oil. Catalysts affected not only the pyrolysis yield, but also the proportions of liquid oil and wax in pyrolysis liquids. Alkenes, alkanes, and aromatics were the main compounds in the pyrolysis liquids. Spent FCC catalyst reduced the production of waxes and increased the production of gasoline-range hydrocarbons and aromatics. MgO catalyst led to high coke formation from polyolefins and PLA. Lactic acid, lactide and propanoic acid were examples of valuable chemicals recovered from the pyrolysis of PLA. Lactide was the main product (up to 79%) of catalytic pyrolysis with zeolite at 400 °C. Spent FCC catalyst produced mostly propanoic acid at 400 °C but at 600 °C, L-lactic acid became the most abundant compound., 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 © 2021 Elsevier Ltd. All rights reserved.)

Extracellular and cell-bound lipase-producing yeasts were isolated from the palm oil mill wastes and investigated for their potential uses as biocatalysts in biodiesel production. Twenty-six yeast strains were qualitatively screened as lipase producers. From those yeast strains, only six were selected and screened further for quantitative lipase production.The phylogenetic affiliations of the yeast strains were confirmed by investigating the D1/D2 domains of 26S rDNA and ITS1-5.8S-ITS2 molecular regions of the six yeast strains selected as potent lipase producers. The three yeast strains A4C, 18B, and 10F showed a close association with Magnusiomyces capitatus. Two yeast strains (17B and AgB) had a close relationship with Saprochaete clavata, whereas the strain AW2 was identified as Magnusiomyces spicifer. Three main catalytic activities of the yeast lipases were evaluated and Magnusiomyces capitatus A4C, among the selected lipase-producing yeasts, had the highest extracellular lipolytic enzyme activity (969 U/L) with the cell-bound lipolytic enzyme activity of 11.3 U/gdm. The maximum cell-bound lipolytic activity (12.4 U/gdm) was observed in the cell-bound lipase fraction produced by Magnusiomyces spicifer AW2 with an extracellular lipolytic enzyme activity of 886 U/L. Based on the specific hydrolytic enzymatic activities, the cell-bound lipases (CBLs) from the three yeast strains M. capitatus A4C, M. spicifer AW2, and Saprochaete clavata 17B were further investigated for biodiesel production. Among them, the CBL from M. spicifer AW2 synthesized the most FAME (fatty acid methyl esters) at 81.2% within 12 h indicating that it has potential for application in enzymatic biodiesel production.

Stress-tolerant oleaginous microalgae are promising for economical outdoor cultivation and biofuel production. This study aimed to induce acclimation and adaptive evolution of oleaginous Scenedesmus sp. SPP to tolerate crucial outdoor stresses by stepwise increasing of physicochemical factors: salinity, light intensity and temperature. The acclimatized strains showed better growth and accumulated 20-30% higher contents of lipids and chlorophylls. The adaptive-evolved strain showed greater tolerance to culture stresses by giving > 2-fold higher biomass under nitrogen rich and accumulating > 1.5-fold higher lipid content under nitrogen starvation compared to the parental strain. Moreover, stepwise increasing of multi-stresses successfully induced the multi-tolerance of the adaptive-evolved strain and gave the highest lipid content of 44.1 ± 1.5%. The extracted lipids from acclimatized/evolved strains show improved prospect fuel properties in terms of high cetane number and oxidative stability. These results show the effectiveness of stepwise-incremental physicochemical factors to intensify potential of microalgae for outdoor cultivation and as biodiesel feedstocks., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Significant components of cost-effective medium for Magnusiomyces capitatus A4C extracellular lipase (ECL) production were optimized via a five-level factorial design. A simplistic, economical, and green approach was adopted for biomimetic mineralization to prepare multilayered nano-entrapped ECL, which were then applied as biocatalysts for the production of fatty acid methyl ester (FAME). The optimal ECL (0.8 mg protein/mL) and CuSO 4 ∙5H 2 O (1.2 mM) showed the highest capacity for enzyme loading. The ECL-CuSO 4 -hybrid showed an 89.7% conversion of triacylglycerides into FAME via transesterification and a 98.7% conversion of oleic acid into FAME via esterification at 72 h. The ECL-CuSO 4 -hybrid gave 65% and 78.7% FAME production after 5 successive reuses via transesterification and esterification reactions, respectively. Therefore, these ECL-inorganic hybrid biocatalysts have high economical potential to be used for the production of biodiesel as the future petrodiesel replacement.

Consolidated bioprocesses for bioconversion of lignocellulosic biomass into biodiesel feedstocks were developed. Palm empty fruit bunch (EFB) was biologically pretreated coupling with fungal lipid production (121.4 ± 2.7 mg/g-EFB) by lignocellulolytic oleaginous fungi prior to lipid production by oleaginous yeasts. In subsequent separate hydrolysis and fermentation (SHF) of fungal pretreated EFB (FPEFB), the oleaginous yeast with the maximum lipid yield of 37.0 ± 0.1 mg/g-FPEFB was screened. While a higher lipid yield of 47.9 ± 1.5 mg/g-FPEFB was achieved in simultaneous saccharification and fermentation (SSF) with less enzyme requirement. Fed-batch SSF of non-sterile FPEFB was proven as a practical and efficient strategy to increase lipid yield up to 53.4 ± 0.5 mg/g-FPEFB. Total lipid yield by both fungi and yeast was 165.0 ± 4.4 mg/g-EFB. Interestingly, the consolidated bioprocesses of enzyme and lipid production also achieved comparable total lipid yield of 149.3 ± 6.6 mg/g-EFB. These strategies may contribute greatly to cost-effective and sustainable bioconversion of lignocellulosic biomass into biodiesel feedstocks., 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.)

The lipolytic oleaginous yeast Yarrowia lipolytica was used in the bioaugmentation and biovalorization of oily industrial wastes during successive-batch fermentation. Five cycles of nonsterile successive batch fermentation with 70% medium replacement achieved the highest oil removal of 68.1 ± 5.60% and produced biomass and lipid yields of 0.213 ± 0.07 g/g-COD and 146.2 ± 46.5 mg/g-COD, respectively. The cell-bound lipase activity observed in the system was 170.74 ± 32 U/L. The auto-flocculation efficiency of the biomass was >90% within 60 Min. The microbial community changes between Y. lipolytica and indigenous microorganisms were monitored by metagenomic next-generation sequencing of internal transcribed spacer rDNA regions for yeasts and 16S rRNA gene for bacteria. Ylipolytica lipolytica was retained in the consortium together with other indigenous strains until the fifth cycle. Other minor oleaginous yeasts such as Kodamaea ohmeri and Candida tropicalis as well as polyhydroxyalkanoate-accumulating bacteria were found and are likely to have participated in lipid production. This study has shown the robustness of Y. lipolytica in nonsterile successive batch fermentation and its use could contribute greatly to the practical valorization of industrial wastes for lipids and lipases., (© 2019 International Union of Biochemistry and Molecular Biology, Inc.)

This paper represents a comprehensive study of two new thraustochytrids and a marine Rhodotorula red yeast isolated from Australian coastal waters for their abilities to be a potential renewable feedstock for the nutraceutical, food, fishery and bioenergy industries. Mixotrophic growth of these species was assessed in the presence of different carbon sources: glycerol, glucose, fructose, galactose, xylose, and sucrose, starch, cellulose, malt extract, and potato peels. Up to 14g DW/L (4.6gDW/L-day and 2.8gDW/L-day) of biomass were produced by Aurantiochytrium and Thraustochytrium species, respectively. Thraustochytrids biomass contained up to 33% DW of lipids, rich in omega-3 polyunsaturated docosahexaenoic acid (C22:6, 124mg/g DW); up to 10.2mg/gDW of squalene and up to 61μg/gDW of total carotenoids, composed of astaxanthin, canthaxanthin, echinenone, and β-carotene. Along with the accumulation of these added-value chemicals in biomass, thraustochytrid representatives showed the ability to secrete extracellular polysaccharide matrixes containing lipids and proteins. Rhodotorula sp lipids (26% DW) were enriched in palmitic acid (C16:0, 18mg/gDW) and oleic acid (C18:1, 41mg/gDW). Carotenoids (87μg/gDW) were mainly represented by β-carotene (up to 54μg/gDW). Efficient growth on organic and inorganic sources of carbon and nitrogen from natural and anthropogenic wastewater pollutants along with intracellular and extracellular production of valuable nutrients makes the production of valuable chemicals from isolated species economical and sustainable., (Crown Copyright © 2020. Published by Elsevier GmbH. All rights reserved.)

Palm biomass wastes are currently considered as promising solid biofuels. However, their high potassium content leads to formation of slag in combustion chambers and causes frequent power-plant shutdowns for maintenance. Therefore, this study aimed to develop a low-cost practical biological pretreatment for these wastes. Oleaginous fungi Aspergillus tubingensis TSIP9, which originates from palm wastes, was used to pretreat biomass wastes and simultaneously produce oils through non-sterile solid state fermentation (SoSF). The operating conditions were optimized through response surface methodology. The fungi could grow and produce oils with good biodiesel fuel properties. After SoSF, potassium content in biomass wastes was reduced by 90% and cellulose content increased to >57%, making it suitable as clean solid biofuel. Repeated-SoSF with 90% substrate replacement was highly effective in continuously pretreating biomass wastes and producing fungal oils. This study demonstrates the cost-effective and environmentally friendly process for production of clean renewable energy through zero-waste strategy., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

This study aimed to control characteristics of fermented rice products by using functional fungi and yeasts isolated from traditional rice cake starters in Thailand. Amylolytic fungi, amylolytic yeasts, alcoholic yeasts and aromatic yeasts were isolated from rice cake starters through different isolation protocols. Among the protocols tested, the enrichment in rice cake fermentation prior to isolation was the most suitable protocol for isolation of amylolytic fungi from all rice cake starters. While the enrichment in submerged fermentation prior to isolation could increase the numbers of yeast isolates. The selected amylolytic fungus and amylolytic yeast were identified as Rhizopus oryzae F63S and Saccharomycopsis fibuligera Y71R, respectively. The yeast with high production of ethanol and aromatic ester was identified as Pichia anomala Y11E. Fermented rice cakes with different characteristics were prepared using various combinations of fungi and yeast. The combination of R . oryzae F63S with S . fibuligera Y71R exhibited strong amylolytic activity and produced an extra sweet fermented rice cake. While the combination of R . oryzae F63S with P. anomala Y11E showed higher alcoholic and aromatic flavors. Moreover, the pure yeast P. anomala Y11E added with commercial amylase has been proven as an innovative starter for fast fermentation. This concept may contribute greatly to the further development of fermented food with desired properties at industrial level.

Oleaginous microalga Scenedesmus sp. was immobilized in alginate-gel beads and applied as two-phase purify unit for biogas and anaerobic digester effluent from palm oil mill. Optimal microalgal cell concentration and bead volume ratio were 10 6 cells mL -1 and 25% v/v, respectively. The use of 20% effluent and light intensity at 128 µmol·proton·m -2  s -1 most promoted CO 2 removal by immobilized microalgae and achieved the maximum CO 2 removal rate of 4.63 kg-CO 2 day -1  m -3 . This process upgraded methane content in biogas (>95%) and completely remove nitrogen and phosphorus in the effluent. After process operation, 2.98 g L -1 microalgal biomass with 35.92% lipid content were recovered by simple sieving method. Microalgal lipids are composed of C16-C18 (>98%) with prospect high cetane number and short ignition delay time. This study has shown the promising biorefinery concept which is effective not only in CO 2 fixation, biogas upgrading and pollutant removal but also cost-effective production of microalgae-based biofuel., (Copyright © 2019 Elsevier Ltd. All rights reserved.)