PROCESS BIOCHEMISTRY
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2015
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IF 2.516
Xiang Zou,Jing Yang,Xu Tian,Meijing Guo,Zhenghua Li,Yunzheng Li
Polymalic acid (PMA) is a water-soluble biopolymer with many attractive properties for pharmaceutical applications. Its monomer, l -malic acid, is a potential C4 platform chemical, which is widely used in the food industry. In this study, a new strain with a high PMA yield from xylose was isolated and identified as Aureobasidium pullulans based on the morphological and phylogenetic analyzes. This strain produced PMA from xylose at a comparable or higher rate than glucose, and PMA produced from xylose had a similar molecular weight to that produced from glucose. A high final PMA titer of 80.4 g/L (91.2 g/L of malic acid after hydrolysis) was achieved using fed-batch fermentation with xylose in a 5-L fermentor at a PMA productivity of 0.52 g/L h. Corncob hydrolysate could be better utilized producing 28.6 g/L of PMA (or 32.4 g/L malic acid) in batch fermentation. PMA was further characterized for its chemical structure. This strain can be used to produce PMA and malic acid from xylose and lignocellulosic biomass hydrolysates.
研究领域:
生物化学
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工业微生物学
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高影响因子
Arabian Journal of Chemistry
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2022
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IF 6.212
Xiaohong Yu,Mian Wang,Yiwen Zhang,Xiaochen Liu,Xiaoyang Zhang,Jinbin Liu,Dujun Wang,Wenbin Jin,Yongmei Lyu
The green and high-value recycling of shrimp shell and straw remains a worldwide problem. This study aimed to investigate the potential utilization of a fermentation broth (FB) which contains shrimp shell and straw as a new source for preparation of biodegradable films. Aureobasidium pullulans and Photobacterium sp. LYM-1 were used in the fermentation. The cellulase activity was 115.92 U/mL and chitinase activity was 17.89 U/mL in FB. The polysaccharides concentration in FB was 1.05 mg/mL after 7 days of fermentation. An eco-friendly PVA-reinforced FB biodegradable film (FBBF) was successfully prepared and the effect of different plasticizers and surfactants on the mechanical, structural, and impermeability properties of the film was determined. The formation of new bonds between PVA and FB was proved by FTIR spectroscopy. The FBBF containing 0.25 % ( w/v ) glycerol and 0.01 % ( v/v ) tween-20 showed better strength properties. Elongation and water-swelling properties were highly improved by adding 0.2 % ( m/v ) citric acid. According to FE-SEM images, the smooth and tight surface of citric acid added FBBF was observed. Interestingly, the FBBF film showed good heat/moisture capacity, antifungal, and degradation properties. This report reveals a new green, and high-value recycling of straw and shrimp shell by the co-fermentation with A. pullulans and Photobacterium sp. LYM-1. It is also a novel way for the preparation of biodegradable film.
研究领域:
生物技术
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环境科学
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材料科学
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微生物学
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废物管理
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2023
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IF 8.2
Dongdong Zeng,Yutian Zhang,Xiaojun Ma,Jianing Li,Fen Yin,Dongna Li,Wenxuan Bie
Co-fermentation of multiple substrates has emerged as the most effective method to improve the yield of bioproducts. Herein, sustainable rubberwood enzymatic hydrolysates (RWH) were co -fermented by Aureobasidium pullulans to produce poly(β-L-malic acid) (PMA), and RWH + glucose/xylose was also investigated as co-substrates. Owing to low inhibitor concentration and abundant natural nitrogen source content of RWH, a high PMA yield of 0.45 g/g and a productivity of 0.32 g/L/h were obtained by RWH substrate fermentation. After optimization, PMA yields following the fermentation of RWH + glucose and RWH + xylose reached 59.92 g/L and 53.71 g/L, respectively, which were 52 % and 36 % higher than that after the fermentation of RWH. RWH + glucose more significantly affected the correlation between PMA yield and substrate concentration than RWH + xylose. The results demonstrated that the co-fermentation of RWH co-substrate is a promising method for the synthesis of bioproducts.
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PubMed
高影响因子
PLoS One
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2015
·Vol. 10
·期 3
·e0121416
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IF 3.234
Xiang Zou,Yongkang Wang,Guangwei Tu,Zhanquan Zan,Xiaoyan Wu
Malic acid is a dicarboxylic acid widely used in the food industry, and is also a potential C4 platform chemical. Corncob is a low-cost renewable feedstock from agricultural industry. However, side-reaction products (furfural, 5-hydroxymethylfurfural (HMF), formic acid, and acetic acid) that severely hinder fermentation are formed during corncob pretreatment. The process for producing malic acid from a hydrolysate of corncob was investigated with a polymalic acid (PMA)-producing Aureobasidium pullulans strain. Under the optimal hydrolysate sugar concentration 110 g/L, A . pullulans was further adapted in an aerobic fibrous bed bioreactor (AFBB) by gradually increasing the sugar concentration of hydrolysate. After nine batches of fermentation, the production and productivity of malic acid reached 38.6 g/L and 0.4 g/L h, respectively, which was higher than that in the first batch (27.6 g/L and 0.29 g/L h, respectively). The adapted strain could grow under the stress of 0.5 g/L furfural, 3 g/L HMF, 2g/L acetic acid, and 0.5 g/L formic acid, whereas the wild type did not. Transcriptome analysis revealed that the differentially expressed genes were related to carbohydrate transport and metabolism, lipid transport and metabolism, signal transduction mechanism, redox metabolism, and energy production and conversion under 0.5 g/L furfural and 3 g/L HMF stress conditions. In total, 42 genes in the adapted strain were upregulated by 15-fold or more, and qRT-PCR also confirmed that the expression levels of key genes (i.e. SIR , GSS , CYS , and GSR ) involved in sulfur assimilation pathway were upregulated by over 10-fold in adapted strain for cellular protection against oxidative stress.
研究领域:
微生物学
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生物技术
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生物化工
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分子生物学
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DOI
PubMed
高影响因子
Chemical and Biological Technologies in Agriculture
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2026
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IF 5.8
Tian Shu,Cheng Feng,Wu Pan,Jia Xuewei,Qu Lili,Xu Chunping
Background Microbial exopolysaccharides (EPS) are renewable biopolymers of increasing importance in the agri-food sector, and producing them from low-cost substrates offers a route to valorize agro-industrial resources. Aureobasidium pullulans is an industrially important fungus that secretes the α-glucan pullulan; however, the structure of the EPS it produces under lactose fermentation—a means of upgrading a low-value, dairy-derived carbon source—has not been clearly defined, which limits its rational use as an agri-food bioproduct. This study aimed to produce, structurally characterize, and preliminarily evaluate the physiological activity of this EPS. Results A homogeneous EPS was obtained by ethanol precipitation, Sevag deproteinization, and gel-filtration chromatography. Fourier-transform infrared spectroscopy indicated an α-configured, neutral polysaccharide, and gas chromatography identified glucose as the sole monosaccharide. Size-exclusion chromatography coupled with multi-angle laser light scattering showed a high-molecular-weight polymer. One- and two-dimensional NMR analyses established that the EPS is a linear pullulan-type α-D-glucan with the repeating unit [→6)-α-D-Glcp-(1→4)-α-D-Glcp-(1→4)-α-D-Glcp-(1→] n, in which two α-(1→4)-linked glucose residues alternate with an α-(1→6) linkage. In a high-fat-diet-induced obese rat model, dietary supplementation with the glucan attenuated body-weight gain, improved serum lipid profiles (TG, TC, HDL-C/TC), and lowered serum endotoxin and tumour necrosis factor-α, together with enhanced colonic short-chain fatty acid production, consistent with fermentation of the glucan by the gut microbiota. Conclusions Lactose fermentation by A. pullulans yields a structurally defined, linear pullulan-type α-D-glucan, demonstrating a route to convert a low-value dairy-derived substrate into a value-added biopolymer. Its prebiotic-associated metabolic effects indicate potential as a functional ingredient for the agri-food chain and warrant further mechanistic and safety studies. Graphical abstract
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高影响因子
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