Foods
·
2023
·Vol. 12
·期 18
·3350
·
IF 5.2
Yuhan Wang,Hongjuan Mo,Zhihong Hu,Bingjie Liu,Zhiqian Zhang,Yaowei Fang,Xiaoyue Hou,Shu Liu,Guang Yang
Chitooligosaccharides (COS), a high-value chitosan derivative, have many applications in food, pharmaceuticals, cosmetics and agriculture owing to their unique biological activities. Chitosanase, which catalyzes the hydrolysis of chitosan, can cleave β-1,4 linkages to produce COS. In this study, a chitosanase-producingBacillus paramycoidesBP-N07 was isolated from marine mud samples. The chitosanase enzyme (BpCSN) activity was 2648.66 ± 20.45 U/mL at 52 h and was able to effectively degrade chitosan. The molecular weight of purifiedBpCSN was approximately 37 kDa. The yield and enzyme activity ofBpCSN were 0.41 mg/mL and 8133.17 ± 47.83 U/mg, respectively. The optimum temperature and pH ofBpCSN were 50 °C and 6.0, respectively. The results of the high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC) of chitosan treated withBpCSN for 3 h showed that it is an endo-chitosanase, and the main degradation products were chitobiose, chitotriose and chitotetraose.BpCSN was used for the preparation of oligosaccharides: 1.0 mg enzyme converted 10.0 g chitosan with 2% acetic acid into oligosaccharides in 3 h at 50 °C. In summary, this paper reports thatBpCSN has wide adaptability to temperature and pH and high activity for hydrolyzing chitosan substrates. Thus,BpCSN is a chitosan decomposer that can be used for producing chitooligosaccharides industrially.Keywords:Bacillus paramycoides;chitosanase;chitosan;chitosan oligosaccharides;enzymatic properties
研究领域:
微生物学
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生物技术
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生物化学
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PubMed
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Microorganisms
·
2023
·Vol. 11
·期 8
·1989
·
IF 4.5
Xiaoyu Cao,Jingyuan Cai,Yu Zhang,Chao Liu,Meijie Song,Qianqian Xu,Yang Liu,Hai Yan
High serum uric acid levels, known as hyperuricemia (HUA), are associated with an increased risk of developing gout, chronic kidney disease, cardiovascular disease, diabetes, and other metabolic syndromes. In this study, a promising bacterial strain capable of biodegrading uric acid (UA) was successfully isolated fromBaijiucellar mud using UA as the sole carbon and energy source. The bacterial strain was identified asBacillus paramycoides-YC02 through 16S rDNA sequence analysis. Under optimal culture conditions at an initial pH of 7.0 and 38 °C, YC02 completely biodegraded an initial UA concentration of 500 mg/L within 48 h. Furthermore, cell-free extracts of YC02 were found to catalyze and remove UA. These results demonstrate the strong biodegradation ability of YC02 toward UA. To gain further insight into the mechanisms underlying UA biodegradation by YC02, the draft genome of YC02 was sequenced using Illumina HiSeq. Subsequent analysis revealed the presence of gene1779 and gene2008, which encode for riboflavin kinase, flavin mononucleotide adenylyl transferase, and flavin adenine dinucleotide (FAD)-dependent urate hydroxylase. This annotation was based on GO or the KEEG database. These enzymes play a crucial role in the metabolism pathway, converting vitamin B2to FAD and subsequently converting UA to 5-hydroxyisourate (HIU) with the assistance of FAD. Notably, HIU undergoes a slow non-enzymatic breakdown into 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) and (S)-allantoin. The findings of this study provide valuable insights into the metabolism pathway of UA biodegradation byB. paramycoides-YC02 and offer a potential avenue for the development of bacterioactive drugs against HUA and gout.Keywords:uric acid;Bacillus paramycoides-YC02;biodegradation;genomic analysis
研究领域:
微生物学
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基因组学
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代谢研究
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生物技术
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BIOCATALYSIS AND BIOTRANSFORMATION
·
2023
·
IF 1.8
Zhi Chen,Zhaohe Dong,Xin Ju,Lishi Yan,Liangzhi Li,Donzhi Wei
6-Hydroxynicotinic acid emerged as a pivotal intermediate for fine chemicals. The current study aims to screen novel nicotinate dehydrogenase-producing strains. Based on the high-throughput UV coloration method, a novel nicotinate dehydrogenase-producing strain named Bacillus paramycoides was first and successfully screened from soil and gram staining as 16S rRNA gene sequencing was conducted to further confirm its accuracy. The fermentation medium formula is determined as seignette salt (5 g/L), tryptone (10 g/L), K2HPO4 (2 g/L), and nicotinic acid (4 g/L) after a single factor and orthogonal test. The activity of nicotinate dehydrogenase produced by B. paramycoides after optimization reached 1.23 U/mL, which was the highest ever reported. In addition, the enzyme characterization results revealed that the optimum reaction temperature and pH were 40 °C and 7.0, respectively. Furthermore, B. paramycoides nicotinate dehydrogenase exhibited good thermostability with more than 50% of the highest enzyme activity retained at 50 °C after 8 h incubation, which was better than ever reported. The pH stability results suggested that nicotinate dehydrogenase possessed a narrow pH ranging from 6.0 to 8.0. In addition, shaker speed demonstrated a positive relation with enzyme activity since shaker speed could affect mass transfer and dissolved oxygen concentration. Finally, it could completely transform nicotinic acid to 6-HNA within 3 h when the substrate loading is 15 g/L. In conclusion, these results indicated that B. paramycoides nicotinate dehydrogenase could serve as a potential candidate for bioproduction of 6-HNA.
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ANTONIE VAN LEEUWENHOEK INTERNATIONAL JOURNAL OF GENERAL AND MOLECULAR MICROBIOLOGY
·
2026
·Vol. 119
·期 9
·205
·
IF 2
Raj Pranay,Sharma Harshit Kumar,Selvaraj Venkatesan,Pandey Abhay Kumar
The present research investigates the chemical profile of secondary metabolites produced by Bacillus paramycoides BOK01 and Microbacterium barkeri BPATH02 rhizospheric bacteria originating from the tea rhizosphere and their antifungal activity against major tea pathogens. GC–MS analysis revealed that dimethyl sulphate (77.09%) was a major compound (Compound I ) of B. paramycoides BOK01 and 1H-Purin-6-amine, [(2-fluorophenyl) methyl- (CAS) (Compound II; 16.88%), and docosane (Compound III; 11.75%) as putative major compounds in M. barkeri BPATH02. Furthermore, the ethyl acetate extract of both bacterial antagonists and compounds I, II , and III were evaluated for their efficacy against major tea pathogens, namely Exobasidium vexans , Pseudopestalotiopsis theae, and Fusarium concentricum causing respective blister blight, gray blight, and Fusarium dieback in tea crops using two-sealed-base-plate method. Laboratory screening of ethyl acetate (EA) extracts of both bacterial antagonists at 200 µg/mL provided a 65.95 to 82.5% range of growth inhibition of tested pathogens. At similar dose, compounds I, II, and III provided 70.88 to 77.53%, 67.7 to 78.0% and 71.8 to 73.07% range of growth inhibition of tested pathogens, respectively. Thus, this study shows that bacterial metabolites and their compounds are sources of putative antifungal agents, which can be harnessed for bio-fungicides development against tea diseases.
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