EXTREMOPHILES
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2018
·Vol. 22
·期 3
·473-484
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IF 2
Chen Kun,Mo Qingshan,Liu Huan,Yuan Feiyan,Chai Haonan,Lu Fuping,Zhang Huitu
A psychrophilic extracellular protease was isolated from the marine bacterium Planococcus sp. M7 found in the deep-sea mud of the Southern Indian Ocean. The mature protease is about 43 kDa and contains 389 amino acids. Sequence alignment revealed that the protease whose catalytic triad was comprised of Ser224, Lys249, and Gln253 contains a catalytic module belonging to the serralysin-type protease family 41, and displays 46.55% identity with the experimentally verified serine protease from Bacillus subtilis str. 168. The enzyme displayed an alkaline mesophilic preference with an optimum pH of 10.0 and an optimum temperature of 35 °C. The enzyme retained its activity from 5 to 35 °C and was resistant to repeated freezing and thawing, but was completely inactivated at 55 °C. Calcium ions had a protective effect against thermal denaturation. More than 60% of the maximum activity was retained at pH values in the range of 5.0–11.0. Almost no activity loss was detected after 1 h of incubation at pH 8.0–10.0 and 20 °C, or with 1.0% SDS. Most important, this protease also showed good stability and compatibility with the standard enzyme-free detergent, which indicates its special interest for applications in detergent industry.
研究领域:
微生物学
·
生物化学
·
酶学
·
海洋生物学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Yuyu Zhang,Tao Zhang,Wanling Cai,Gary Owens,Zuliang Chen
While microbial technologies, which are considered to be environmentally friendly, have great potential for the recovery of rare earth elements (REEs) from mining wastewater, their applications have been restricted due to a lack of efficient biosorbents. In this study, a strain of Pseudomonas psychrotolerans isolated from yttrium-enriched mine soil was used to recover yttrium (Y(III)) from rare-earth mining wastewater. At an initial Y(III) dose of 50 mg L −1 , the amount of Y(III) adsorbed by P. psychrotolerans reached 99.9 % after 24 h. Various characterization techniques revealed that P. psychrotolerans adsorbed Y(III) mainly through complexation of oxygen-containing functional groups and electrostatic interactions. A high level of adsorption efficiency (>99.9 %) was maintained after five consecutive adsorption/desorption cycles, indicating that P. psychrotolerans was highly reusable. While the efficiency of adsorbing Y(III) by P. psychrotolerans decreased (34.4 %) in actual rare earth mining wastewater, selectivity toward other REEs (≤ 18.4 %) was still observed. Consequently, this study provides a promising green, environmentally friendly and sustainable microbial approach for the selective recovery of REEs from rare earth wastewater.
研究领域:
环境科学
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微生物学
·
废水处理
·
生物技术
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产品关联
DOI
PubMed
高影响因子
POSTHARVEST BIOLOGY AND TECHNOLOGY
·
2020
·
IF 4.303
Feng Wang,Qingzhen Yang,Qifeng Zhao,Xiaoping Zhang
To investigate the effects of fruit maturity on chilling injury, antioxidative capacity, and energy metabolism, ‘Hongyang’ kiwifruit were harvested at three stages of maturity (I, II, and III), based on soluble solid content (4.5–5.5 %, 6.5–7.5 %, and 8.5–9.5 %, respectively). The fruit were cold-stored at 0 °C for 100 d and then subjected to various analyses. Among the three fruit stages, stage II and III fruit were less susceptible to chilling injury and exhibited a higher abundance of antioxidant enzymes (superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase) and energy and metabolism-related enzymes (H + -adenosine triphosphatase, Ca 2+ -adenosine triphosphatase, cytochrome C oxidase, and succinic dehydrogenase). Moreover, we observed lower levels of super oxide anion, H 2 O 2 , malondialdehyde content, and relative membrane permeability, and higher levels of ATP and energy charge. These results indicated that the higher resistance of stage II and III ‘Hongyang’ kiwifruit against chilling injury could be correlated to higher antioxidant and energy metabolism-related enzyme activities, ATP levels, and energy charges. However, the stage III fruit decayed faster than stage II fruit. The results indicate that the postharvest life of ‘Hongyang’ kiwifruit can be maximized by harvesting and storing kiwifruit at a soluble solids content of 6.5–7.5 %.
研究领域:
植物生理学
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采后科学
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食品科学
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产品关联
DOI
高影响因子
Food Science and Human Wellness
·
2023
·
IF 7
Weijun Leng,Xiaoyun Wu,Xianghui Qi,Hongying Liu,Li Yuan,Ruichang Gao
In this study, a gene encoding serine protease ( PmSpr288 ) from cold-adapted bacterium, namely Planococcus maritimus XJ11, was cloned and overexpressed in Escherichia coli BL21 (DE3). Bioinformatics analysis revealed that PmSpr288 belongs to serine protease S8 superfamily with a classical catalytic triad comprised by the Asp49, His86 and Ser251. Moreover, PmSpr288 was found to be active over broad alkaline pH and low-moderate temperature, and exhibited wide range of protein substrate specificity. In addition, PmSpr288 was able to hydrolyze the meat proteins actin and myosin, and molecular docking results suggested that the crucial interaction between PmSpr288 and actin/myosin complexes was mainly occupied by hydrogen bonds. The muscle protein hydrolysates of silver carp prepared by PmSpr288 was shown to have antioxidant activity via DPPH radical scavenging assay, which presented an IC 50 valve of 1.309 mg/mL. In conclusion, these characteristics imply that PmSpr288 has potential biotechnological application prospect for the production of bioactive peptides.
研究领域:
微生物学
·
生物化学
·
生物技术
·
食品科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）