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Lin X.,Fuzhou University | Ye X.,Fuzhou University | Ye X.,Fujian Provincial Key Laboratory of Marine Enzyme Engineering | Wang G.,Fuzhou University | And 5 more authors.
Journal of Chinese Institute of Food Science and Technology | Year: 2016

[Objective] Xylanase-producing strains were screened from different sources of samples. The strain which had largest xylanase yield was identified and its xylanase properties were studied. [Methods] With self-made xylan as the only carbon source, the xylnase-producing strains had been screened according to the transparent zone on the plate. The strain was identified based on the morphological characteristics observation and 16S rDNA sequence analysis. [Results] The 27 of 44 strains which showed transparent zones had xylanse -producing ability and B659 was the highest among them. B659 was identified as Bacillus stratosphericus. The optimal temperature and pH of B659 xylanse was 55℃ and 6.5.78% of xylanse activity was retained after 2 h incubation at 37℃ and pH 8-10 and it performed great alkali resistance. Besides, 10 mmol/L K+ and 1 mmol/L Fe2+ displayed promotion effect to xylnase ability while Mn2+, Cu2+ and Co2+ manifested obvious inhibition. [Conclusion] Bacillus stratosphericus B659 with high ability to produce alkali-resistance xylanase was screened. © 2016, Chinese Institute of Food Science and Technology. All right reserved. Source


Zhou Z.,Fuzhou University | Zhou Z.,Fujian Provincial Key Laboratory of Marine Enzyme Engineering | Lin J.,Fuzhou University | Lin J.,Fujian Provincial Key Laboratory of Marine Enzyme Engineering | And 6 more authors.
Journal of Chinese Institute of Food Science and Technology | Year: 2015

Objective: Lipase-producing marine microorganisms were isolated and identified, and the enzymatic properties were studied. Methods: Lipase-producing marine microorganisms were isolated with selective mediacontained olive oil as the only source of carbon. The objective strain was identified according to the sequence analysis of 16S rDNA, and the enzymatic properties were studied. Results: Twenty-twolipase-producing marine microorganisms were isolated from five samples, such as the intestinal contents of eeland soil samples. The lipase produced by strain ZF-16 had the highest activity to catalyze glycerolysis of oil. Strain ZF-16 was identified as Burkholderiacepacia according to its morphology characteristics and the sequence of 16S rDNA. The optimal pH and temperature of the lipase were pH 9.0 and 75℃, respectively. Activity of lipase was relatively stable at 40℃ and pH 5.0-10.0. Besides, the activity of lipase wasactivated by 1 mmol/L Na+ and K+, and strongly inhibited by Zn2+. The lipase could degrade substrates with different chain length from C4 to C18, especially tricaprylin (C8). Conclusion: A lipase-producing marine microorganism was successfully isolated and identified as Burkholderiacepacia. The results showed that the lipase was a kind of alkaline lipases resisting to high temperature, and had degradation effects on substrates with different chain length from C4 to C18. Therefore, this lipase could be used in food baking, pulp and paper industryand waste-paper deinking. © 2015, Chinese Institute of Food Science and Technology. All right reserved. Source


Lin X.,Fuzhou University | Lin X.,Fujian Provincial Key Laboratory of Marine Enzyme Engineering | Lin J.,Fuzhou University | Lin J.,Fujian Provincial Key Laboratory of Marine Enzyme Engineering | And 6 more authors.
Journal of Chinese Institute of Food Science and Technology | Year: 2015

Xylanases were widely studied, however, most xylanase producing strains were found in the land. The research of xylanases frommarine microorganisms is still rarely reported. A Bacillus sp. strain B659, which was previously screened in water samples from Fujian Pingtan, has a high xylanase yield. This study focused on the optimization of medium components and fermentation conditions to increase the production of xylanase by strain B659.The optimized liquid culture medium for xylanase production was 6% wheat bran, 1% bean cake powder, 10 mmol/L K2HPO4, with initial culture pH 6.0. The optimized medium resulted in a 1.6-fold increase of xylanase yield. The innoculation volume of 8% and culture volume of 25 mL/250 mL were optimum for xylanase production. When strain B659 was incubated at 30℃ with shaking speed of 230 r/min for 30 hours, the xylanase activity has a 0.7-fold increase than before. After the optimization of medium components and fermentation conditions, the xylanase activity reached 2 838 U/mL, which increased by 3.4 times totally. © 2015, Chinese Institute of Food Science and Technology. All right reserved. Source


Wang G.,Fuzhou University | Wang G.,Fujian Provincial Key Laboratory of Marine Enzyme Engineering | Lin J.,Fuzhou University | Lin J.,Fujian Provincial Key Laboratory of Marine Enzyme Engineering | And 6 more authors.
Journal of Chinese Institute of Food Science and Technology | Year: 2015

Objective: Kombucha was fermented with Saccharomyces cerevisiae, Gluconacetobacter sp and Lactobacillus plantarum isolated by our lab, and its antimicrobial action and oxidation resistance was studied. Method: Saccharomyces cerevisiae, Gluconacetobacter sp and Lactobacillus plantarum were mixed at the volume ratio of 1:1:1 and fermerited to produce Kombucha. The contents of major components in Kombucha, such as acetic acid, L-lactic acid, citric acid, reducing sugar, ethanol, tea polyphenols, caffeine, free amino-acid and protein, were determined to investigate the relationship between the major components, antimicrobial activity and antioxidation. Results: The fermentation broth of Kombucha could inhibit six tested pathogenic bacteria strongly, including Epidericha coli, Salmonella enteritidis, Shigella dysenteriae, Listeria monocytogenes, Pseudomonas fluorescens and Staphylococcus aureus. The antibacterial ingredients of Kombucha broth contained not only tea polyphenols, but also organic acids (mainly acetic acid) and heat-resistant materials produced during metabolic process. Furthermore, Kombucha broth had strong antioxidant activity. The hydroxyl radical, DPPH and superoxide anions scavenging abilities of Kombucha were 35.00%, 60.07% and 3.80%, respectively. The reducing power was 1.11. The antioxidant activity was related to the content of tea polyphenols. ©, 2015, Chinese Institute of Food Science and Technology. All right reserved. Source

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