BIOTECHNOLOGY LETTERS
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2022
·Vol. 44
·期 4
·623-633
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IF 2.716
Hao Zhi-kui,Li Jian-song,Wang Dan-hua,He Fei,Xue Jing-shi,Yin Liang-hong,Zheng Hua-bao
Objectives Shellfish waste is a primary source for making N -acetyl- d -glucosamine. Thus, establishing a high-efficiency and low-cost bioconversion method to produce N -acetyl- d -glucosamine directly from shellfish waste was promising.
Results A mutant C81 was obtained from Chitinolyticbacter meiyuanensis SYBC-H1 via 60 Co-γ irradiation. This mutant C81 showed the highest chitinase activity of 9.8 U/mL that was 85% higher than the parent strain. The mutant C81 exhibted improved antioxidant activities, including total antioxidant capacity, superoxide radical ability, and hydroxyl radical scavenging ability, compared to that of the parent strain. Four out of nine organic solvents increased the chitinase activity by 1.9%, 6.8%, 11.7%, and 15.8%, corresponding to methylbenzene, n-heptane, petroleum ether, and n-hexane, respectively. The biphase system composed of aqueous and hexane presented a five-fold reduction of cell viability compared to the control. Using a continuous fermentation bioconversion process, 4.2 g/L GlcNAc was produced from crayfish shell powder with a yield of 80% of the chitin content. Conclusions This study demonstrated that the mutant C81 is suitable for converting crayfish shell powder into GlcNAc in an aqueous-organic system.
研究领域:
微生物学
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生物化学
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生物工程
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DOI
PubMed
高影响因子
WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY
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2017
·Vol. 33
·期 2
·1-14
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IF 1.658
Guan Jian,Shen Songdong,Wu Hao,Liu Xin,Shen Weijie,He Yuan,Duan R.
The filamentous Cyanobacterium Arthrospira is commercially produced and is a functional, high-value, health food. We identified 5 low temperature and low light intensity tolerant strains of Arthrospira sp. (GMPA1, GMPA7, GMPB1, GMPC1, and GMPC3) using ethyl methanesulfonate mutagenesis and low temperature screening. The 5 Arthrospira strains grew rapidly below 14 °C, 43.75 μmol photons m −2 s −1 and performed breed conservation at 2.5 °C, 8.75 μmol photons m −2 s −1 . We used morphological identification and molecular genetic analysis to identify GMPA1, GMPA7, GMPB1 and GMPC1 as Arthrospira platensis , while GMPC3 was identified as Arthrospira maxima . Growth at different culture temperatures was determined at regular intervals using dry biomass. At 16 °C and 43.75 μmol photons m −2 s −1 , the maximum dry biomass production and the mean dry biomass productivity of GMPA1, GMPB1, and GMPC1 were 2057 ± 80 mg l −1 , 68.7 ± 2.5 mg l −1 day −1 , 1839 ± 44 mg l −1 , 60.6 ± 1.8 mg l −1 day −1 , and 2113 ± 64 mg l −1 , 77.7 ± 2.5 mg l −1 day −1 respectively. GMPB1 was chosen for additional low temperature tolerance studies and growth temperature preference. In winter, GMPB1 grew well at mean temperatures <10 °C, achieving 3258 mg dry biomass from a starting 68 mg. In summer, GMPB1 grew rapidly at mean temperatures more than 28 °C, achieving 1140 mg l −1 dry biomass from a starting 240 mg. Phytonutrient analysis of GMPB1 showed high levels of C-phycocyanin and carotenoids. Arthrospira metabolism relates to terpenoids, and the methyl- d -erythritol 4-phosphate pathway is the only terpenoid biosynthetic pathway in Cyanobacteria. The 1-deoxy- d -xylulose 5-phosphate reductoisomerase (DXR) gene from GMPB1 was cloned and phylogenetic analysis showed that GMPB1 is closest to the Cyanobacterium Oscillatoria nigro-viridis PCC711. Low temperature tolerant Arthrospira strains could broaden the areas suitable for cultivation, extend the seasonal cultivation time, and lower production costs.
研究领域:
微生物学
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生物化学
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遗传学
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PubMed
高影响因子
Food Bioscience
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2025
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IF 5.9
Lei Li,Han Lu,Yuling Xue,Yannan He,Baohua Zhao,Lianzhong Ai,Shijie Wang
Probiotic fermented milk has emerged as a prominent functional food for its substantial role in promoting intestinal health and overall wellness. However, a persistent challenge in the industry is post-acidification, a process where lactic acid bacteria continue fermenting during storage, leading to excessive acidity, textural degradation, and flavor alterations. This study focuses on the identification and characterization of a naturally mutated strain of Lacticaseibacillus paracasei capable of significantly attenuating post-acidification in fermented milk. A novel mutation was discovered in the α-glucosidase gene (AF91_03255), wherein the substitution of arginine at position 477 with glycine altered the enzyme's binding dynamics. This mutation enhanced binding stability between the enzyme and its substrate by approximately 16.8%, indirectly modulating acid production without directly limiting glucose metabolism. Through a combination of multi-omics techniques, including metabolomics and genomic sequencing, this study revealed significant shifts in the glycerophospholipid metabolic pathway, suggesting alterations in cell membrane composition as a core mechanism. Additionally, comparative analyses between the wild-type and mutant strains demonstrated notable differences in acid production, viable cell counts, and storage stability. The mutant strain maintained a higher pH and reduced titratable acidity during extended storage while preserving bacterial viability, distinguishing it from traditional approaches reliant on additives or processing modifications. The findings underscore the potential of α-glucosidase as a pivotal target for post-acidification regulation in fermented milk products. Furthermore, this work contributes valuable insights into the strain improvement strategies essential for advancing the stability and sensory qualities of fermented milk.
研究领域:
食品科学
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微生物学
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高影响因子
RSC Advances
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2015
·Vol. 5
·期 17
·12624-12637
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IF 3.84
Haifeng Su,Yun Zhao,Maolin Wang,Yuanjian Xu
Classic chemical mutagenesis has a demonstrated potential to create a strain of Clostridium with improved fermentation performance for obtaining high butanol yield. However, screening methods to select the desired bacterial phenotype from large populations are not currently feasible or readily available. In this paper, a simple, novel screening method to select target strains by using trypan blue dye as an indicator in solid starch media to detect the target mutant bacterium was devised. A well performing mutant strain Clostridium beijerinckii no. 15 was obtained using this screening method. It was derived from wild-type C. beijerinckii NCIMB 8052 by N-methyl-N′-nitro-N-nitrosoguanidine (NTG) mutagenesis, and its fermentative capability for producing butanol was investigated, using hydrolysate of fresh cassava and other substrates. The mutant strain C. beijerinckii no. 15 produced a maximum yield of 15.06 g L−1 butanol and 23.78 g L−1 total solvents, when the fresh cassava substrate was given a simple pretreatment at 121 °C for 1 h. For other substrates, the highest butanol yields: 20.67 g L−1 from glucose, 17.96 g L−1 from liquefied dextrin, and 13.59 g L−1 from liquefied corn powder (P ≤ 0.05) were also achieved. Experimental trials showed that the mutant strain had a significantly greater fermentation ability, and produced a high-yield butanol from fresh cassava hydrolysates. Further research showed that the highest overall yield of butanol resulted from the improvement of enzymatic activity of C. beijerinckii no. 15's α-amylase (P ≤ 0.05). Also, the protein structure of the α-amylase was predicted and its amino acid mutation sites were analyzed. Results revealed that these mutant amino acids may have somehow improved α-amylase activity and thus, led to producing more butanol. Our research will contribute to efforts to develop C. beijerinckii fermentation of fresh cassava to produce butanol.
研究领域:
微生物学
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生物技术
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发酵工程
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2013
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IF 3.548
Ling Jiang,Liying Zhu,Xian Xu,Ming Lin,Yanping Li,Xiaotong Li,Huaiyan Cui,He Huang
Laboratory mutagenesis of microorganisms offers the possibility of relating acquired mutations to improve the quality of microbial cultures. In the present study, a mutant strain, Clostridium tyrobutyricum ATCC 25755 DG-8, with significantly elevated α-amylase activity as well as resistant to the non-metabolizable and toxic glucose analog 2-deoxyglucose (2-DG) was obtained by implanting the low-energy nitrogen ion beam. DG-8 was further developed to produce hydrogen by simultaneous saccharification and fermentation (SSF) directly form cassava starch in batch fermentation mode, which to our knowledge is at the first attempt in genus Clostridium . Our results demonstrated that the increased activity of α-amylase would be attributed to the hydrogen over-producing. Higher hydrogen yield (3.2 mol/mol glucose) was achieved with the volumetric productivity of 0.41 L/h/L when the initial total sugar concentration of cassava starch rise up to 100 g/L. The present work will help to decrease the cost of hydrogen fermentation process and stimulate its industrial application in the near future.
研究领域:
微生物学
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生物工程
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高影响因子
JOURNAL OF BIOTECHNOLOGY
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2025
·
IF 3.9
Chengtuo Niu,Huating Chen,Jinjing Wang,Chunfeng Liu,Qi Li
In beer production, lager yeasts are subjected to harsh environment in high-gravity brewing (HGB, 24°P or more), thus leading to reduced fermentation performance, increased mortality and formation of off-flavors. This study aimed to improve the vitality, viability and fermentation characteristics of lager yeast during HGB through the accumulation of intracellular proline and to reveal the potential mechanism. A mutant lager yeast Y-100 with significantly increased intracellular proline fluorescence intensity of 37.37 % was obtained by Atmospheric and Room Temperature Plasma (ARTP) mutagenesis. Compared to parental YY, the mutant Y-100 had 13.94 % higher intracellular ATP content, 23.01 % lower ROS accumulation and 77.71 % lower mortality rate at the end of serial batch fermentation for 5 times. Moreover, the time for beer matureness by Y-100 strain was shorted by one day while the real degree of fermentation value was 2.76 % higher using 24°P wort. Through genome resequencing, RT-qPCR analysis and gene knockout and overexpression, the up-regulation of GNP1 and SUA7 genes in Y-100 strain might contribute to the proline accumulation in lager yeast cells, thus resulting in energy supply and stress protection for lager yeast during HGB. The results not only provided new insights into the role of proline in lager yeast towards unfavorable industrial condition, but also obtained a high-efficient Y-100 strain for potential HGB application.
研究领域:
微生物学
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发酵工程
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食品科学
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DOI
PubMed
高影响因子
WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY
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2023
·Vol. 39
·期 11
·1-17
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IF 4.1
Song Xiaohui,Li Tang,Gu Hui,Yin Heng
Aspergillus is a well-studied fungal genus that is widely used in the processing of plant biomass in industries. This study investigated the effects of space exposure on the ability of Aspergillus costaricaensis , a filamentous fungus isolated from rotten orange peel, to degrade pectin. These fungal spores were carried into space by the Long March 5B carrier rocket and exposed to cosmic radiation for 79 h. After the flight, these spores were resuscitated, and then the growing strains were screened with pectin as the sole carbon source, and the pectinase activity was evaluated. A mutant with increased biomass accumulation ability and pectin-degrading activity compared to the ground control strain was obtained. Comparative transcriptome analysis revealed that several CAZymes genes were significantly upregulated in the mutant, especially those related to pectin degradation. Among the 44 pectinases identified from the annotated genome, 42 were up-regulated. The activities of these pectinases are able to synergistically break down the structure of pectin. In addition, the expression of some genes involved in metabolism, sugar transport, and stress response was altered. These results imply that space exposure might serve as a potential mutagenesis breeding technique, offering the opportunity to acquire biomass-degrading microbial strains with potential for industrial application.
研究领域:
微生物学
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分子生物学
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生物技术
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DOI
高影响因子
BIORESOURCE TECHNOLOGY
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2011
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IF 4.365
Yuefang Deng,Shuang Li,Qing Xu,Min Gao,He Huang
A mutant strain with high glucoamylase activity and insensitive to catabolite repression was developed to produce fumaric acid by simultaneous saccharification and fermentation (SSF) of starch without additional commercial glucoamylase supplementation. A series of mutant strains resistant to the non-metabolizable and toxic glucose analog 2-deoxyglucose (2-DG) were obtained by implanting nitrogen ion (N + ) into Rhizopus oryzae ME-F12. Among them, the best mutant strain DG-3 produced 39.80 g/L fumaric acid, which is 1.28-fold of that produced by ME-F12, and exhibited higher glucoamylase activity during SSF. Higher fumaric acid production (44.10 g/L) was achieved when the initial total sugar concentration of cornstarch was 100 g/L. During SSF of cheap, raw bioresource-degermed corn powder (100 g/L total sugar) by DG-3, the maximum fumaric acid concentration and productivity were 32.18 g/L and 0.44 g/(L h), respectively.
研究领域:
生物工程
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微生物学
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产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
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2024
·
IF 10.7
Chunxia Chen,Shujie Duan,Jianing Ji,Mengli Wu,Zhan Yang,Mengyang Cai,Menghan Xue,Lanju Wang,Rui Chen,Sima Yaron,Keying Guo,Sergio Benardini,Zhizeng Wang,Yang Luo
Conventional point-of-care lateral flow immunoassays are characterized by an antibody-tagged probe irregular coupling that can limit sensitivity and require a long assay’s time. We synthesized polyethylene glycol-modified selenium nanoparticles (PEG-SeNPs) by template method and developed a strategy to set antibody probes targeted and orderly by using PEG-SeNPs. Synthesized PEG-SeNPs with high stability could immobilize antibodies in the “stand-up” orientation, resulting in a faster detection time of less than 1 min by direct observer visualization without instruments or equipment. Results showed that SARS-CoV-2 antibody could be systematically structured on the chip, resulting in a detection limit of 10 pg/mL, significantly higher than conventional chips. The new device has been validated on 192 clinical samples and we found 100% negative coincidence, 93.94% positive coincidence, and 95.83% overall coincidence with reverse transcriptional PCR test. The orderly arrayed probe’s stability allowed to detect throat swabs, saliva, serum, fingertip blood samples, and mutant strains without cross-reactivity with common respiratory viruses or pathogenic strains, demonstrating promising potential for a universal colorimetric platform for ultrafast field-deployable diagnostics.
研究领域:
生物医学工程
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纳米技术
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病毒学
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诊断医学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）