Applied Sciences-Basel
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2021
·Vol. 11
·期 19
·9127
·
IF 2.679
Tianji Liu,Yitong Wang,Junguo Li,Qing Yu,Xiaoman Wang,Di Gao,Fuping Wang,Shuang Cai,Yanan Zeng
The effects of Ca2+in converter slag and electric arc furnace slag leaching solutions on CO2content, the effects of CO2content in solutions on the accumulation of chlorophyll a ofNannochloropsissp., and the mechanisms were studied. Results showed that addition of 50 mg/L converter slag leaching solution and 400 mg/L electric arc furnace slag leaching solution (lower than 50 vol% concentration) promoted the accumulation of chlorophyll a ofNannochloropsissp., while an increased concentration of 70 vol% inhibited its accumulation. The highest concentration of chlorophyll a was obtained on the addition of 10 vol%. With 10 vol% leaching solutions added, chlorophyll a concentration for converter slag reached 4.2 mg/L, 1.45 times as much as that of pure F/2 medium, and chlorophyll a concentration for electric arc slag reached 3.2 mg/L, 1.10 times as much as that of pure F/2 medium. Under the same addition proportion, the promoting or inhibiting effect from converter slag on the accumulation of chlorophyll a ofNannochloropsissp. was more obvious than that for electric arc furnace slag. The reason for the promotion of chlorophyll a accumulation ofNannochloropsissp. was that an increase of Ca2+in the solutions led to an increase of CO2, thereby promoting the photosynthetic rate of microalgae. The study provided new ideas for the green application of solid waste and industrial production of microalgae.Keywords:leaching solutions;converter slag;electric arc furnace slag;Nannochloropsissp.;chlorophyll a;CO2content
研究领域:
环境科学
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微生物学
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高影响因子
3 Biotech
·
2023
·Vol. 13
·期 10
·1-11
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IF 2.8
Zhao Zhenzhen,Liu Yanfeng,Liu Chao,Xu Qianqian,Song Meijie,Yan Hai
Extensive use of phthalic acid esters (PAEs) as plasticizer causes diffusion into the environment, which posed a great threat to mankind. It was reported that Comamonas sp. was a potentially robust aromatic biodegrader. Although the biodegradation of several PAEs by Comamonas sp. was studies, the comprehensive genomic analysis of Comamonas sp. was few reported. In the present study, one promising bacterial strain for biodegrading diethyl phthalate (DEP) was successfully isolated from activated sludge and characterized as Comamonas sp. USTBZA1 based on the 16S rRNA sequence analysis. The results showed that pH 7.5, 30 °C and inoculum volume ratio of 6% were optimal for biodegradation. Initial DEP of 50 mg/L could be completely biodegrade by strain USTBZA1 within 24 h which conformed to the Gompertz model. Based on the Q-TOF LC/MS analysis, monoethyl phthalate (MEP) and phthalic acid (PA) were identified as the metabolic products of DEP biodegradation by USTBZA1. Furthermore, the whole genome of Comamonas sp. USTBZA1 was analyzed to clarify the molecular mechanism for PAEs biodegradation by USTBZA1. There were 3 and 41 genes encoding esterase/arylesterase and hydrolase, respectively, and two genes regions ( pht 34512 and pht 4253) were responsible for the conversion of PA to protocatechuate (PCA), and two genes regions ( lig CBAIKJ) were involved in PCA metabolism in USTBZA1. These results substantiated that Comamonas sp. USTBZA1 has potential application in the DEP bioremediation.
研究领域:
环境生物学
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微生物学
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PubMed
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
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2023
·Vol. 98
·期 4
·1014-1024
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IF 3.4
Diantong Li,Jiayu Li,Balijiang Yeerhazi,Yongtao Cheng
BACKGROUND With the rapid development of modern industry and agriculture, large amounts of sewage of various types are being discharged into water bodies every year, causing huge environmental pressure and posing a threat to organisms. Amongst different solutions to this problem, microalgae can remove pollutants including pesticides and antibiotics from water . In this work, an algal strain designated as Scenedesmus sp. TXH. was isolated from the Tangxun Lake Sewage Treatment Plant (Wuhan, China) and used to remove imidacloprid (IMI) from sewage. The removal efficiency, degradation products, removal of conventional contaminants [total dissolved nitrogen (TDN) ammonia nitrogen (NH 4 + -N), total dissolved phosphorus (TDP)], the biochemical response of the microalgae, and the effects of environmental factors such as light intensity and temperature were investigated. RESULTS The results showed that: (i) the highest IMI removal efficiency of ≈60% was achieved under 80 μmol m −2 s −1 at 25 °C; (ii) the removal of NH 4 + -N, TDP and TDN in the sewage reached 90%, 90% and 65%, respectively; (iii) there was a significant linear relationship between the concentration of total chlorophyll and the removal of IMI in the sewage; and (iv) finally, based on the analysis of degradation products by mass spectrometer, three potential IMI degradation pathways were proposed. CONCLUSION In summary, our results showed that Scenedesmus sp. TXH can remove IMI and conventional nutrients efficiently from sewage, implying a potential application in sewage treatment in the near future. © 2023 Society of Chemical Industry (SCI).
研究领域:
环境科学
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微生物学
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高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
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2021
·Vol. 87
·期 8
·
IF 4.792
Chao-Fan Yin,Ying Xu,Shi-Kai Deng,Wen-Long Yue,Ning-Yi Zhou
As a water-soluble polymer, the widely used polyvinyl alcohol (PVA) is produced from hydrolysis of polyvinyl acetate. Microbial PVA carbon backbone cleavage via a two-step reaction of dehydrogenation and hydrolysis has been well studied. The content of the acetyl group is a pivotal factor affecting performance of PVA derivatives in industrial applications, and deacetylation is a nonnegligible part of PVA degradation. However, the genetics and biochemistry of its deacetylation remain largely elusive. Here, Comamonas sp. strain NyZ500 was isolated for its capability of growing on acetylated PVA from activated sludge. The spontaneous PVA utilization-deficient mutant strain NyZ501 was obtained when strain NyZ500 was cultured in rich media. Comparative analysis between the genomes of these two strains revealed a fragment (containing a putative hydrolase gene, dacApva) deletion in strain NyZ501, and in the dacApva-complemented strain NyZ501 the ability to grow on PVA was restored. DacApva, which shares 21% identity with xylan esterase AxeA1 from Prevotella ruminicola 23, is a unique deacetylase catalyzing the conversion of acetylated PVA and its derivatives to deacetylated counterparts. This indicates that strain NyZ500 utilizes acetylated PVA via acetate as a carbon source to grow. DacApva also possesses the ability to deacetylate acetylated xylan and the antibiotic intermediate 7-aminocephalosporanic acid (7ACA), but the enzymes responsible for the conversion of those two compounds have no activity against PVA derivatives. This study enhanced our understanding of the diversity of microbial degradation of PVA, and DacApva characterized here is also a potential biocatalyst for the eco-friendly biotransformation of PVA derivatives and other acetylated compounds.IMPORTANCE Water-soluble PVA, which possesses a very robust ability to accumulate in the environment, has a very grave environmental impact due to its widespread use in industrial and household applications. On the other hand, chemical transformation of PVA derivatives is currently being carried out under high-energy-consumption and high-pollution conditions using hazardous chemicals (such as NaOH and methanol) under high temperatures. The DacApva reported here performs PVA deacetylation under mild conditions, so it has great potential to be developed into an eco-friendly biocatalyst for biotransformation of PVA derivatives. DacApva also has deacetylation activity for compounds other than PVA derivatives, which facilitates its development into a broad-spectrum deacetylation biocatalyst for production of certain desired compounds.
研究领域:
环境科学
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生物化学
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微生物学
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PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
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IF 7.7
Xiong Li,Chuyi Li,Wanzi Yao,Jian Mao
Carrageenan oligosaccharides have attracted significant attention due to their excellent biological activities, and they can be produced by carrageenases. In this study, a novel marine bacterium, Shewanella sp. LE8, was used to enzymatically degrade carrageenan, and the κ-, ι-, and λ-carrageenases produced by the bacterium were characterized. The crude enzyme derived from media exhibited κ-carrageenase activity, indicating its natural secretion during growth and proliferation. According to the results of molecular weight distribution from HPGPC, λ-carrageenan could be degraded by Shewanella sp. LE8 cells in both 20 mM Tris-HCl buffer and PBS, while ι-carrageenan can only be hydrolyzed in PBS environment, indicating the activation of ι-carrageenase in Shewanella sp. LE8 was dependent on the presence of Na + ions. The components of carrageenan hydrolysates were determined by ESIMS, and results revealed that κ-carrageenan hydrolysates were primarily consisted of G4S-DA, [G4S-DA] 2 and [G4S-DA] 3 , while ι-carrageenan hydrolysates were predominantly composed of [G4S-DA2S] 2 . Moreover, the fragment ions of λ-carrageenan revealed that the hydrolytic process not only encompasses enzymatic cleavage of glycosidic bonds but also involves the participation of sulfatase. The precise structure was further elucidated through NMR analysis, confirming that the end-products of ι-carrageenase were neoι-carratetraose. The results highlight the potential of Shewanella sp. LE8 for industrial applications in the production of ι-carrageenan oligosaccharides.
研究领域:
海洋生物学
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酶学
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生物化学
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PubMed
高影响因子
INTERNATIONAL BIODETERIORATION & BIODEGRADATION
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2023
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IF 4.8
Linna Du,Huan Wu,Gang Li,Yi Wei,Fei Wang,Ligen Xu,Xinjiao Dong
Microbial degradation of dyes is fundamental and essential for understanding their environmental fate . In this study, a new bacterial strain with efficient degrading capability of triphenylmethane (TPM) dyes named WKD was isolated and identified as the genus Serratia sp. by 16S rDNA analysis . The decolorization of TPM dyes by the strain especially under extreme environmental conditions were studied. The results showed that the strain could completely decolorize Malachite Green (MG) and Crystal Violet (CV) at pH values ranging from 3.0 to 10.0 and at temperatures ranging from 20 °C to 45 °C in a 12 h of incubation. The strain still showed an excellent decolorizing capability even at low (5 °C) and high (60 °C) temperatures. Moreover, the enzymatic analysis indicated that MnP, NADH-DCIP reductase, MG reductase, and CV reductase might be involved in TPM dyes biodegradation. Besides, the biodegradation pathways were proposed based on UV–visible, FTIR , and LC-Q-TOF-MS analyses. Results indicated that degradation of MG by the strain was mainly regulated by N-demethylation and hydroxylation pathways, while degradation of CV was only by the N-demethylation pathway. Therefore, Serratia sp. strain WKD is expected to have a broad application prospect for the bioremediation of TPM dyes, especially in extreme environments.
研究领域:
微生物学
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环境科学
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高影响因子
LETTERS IN APPLIED MICROBIOLOGY
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2015
·Vol. 61
·期 4
·390-396
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IF 1.659
Chao H.,Wu B.,Shen P.
Increase in L‐serine production is of interest for industry. Here, we describe a metabolic engineering approach to increase the production of L‐serine in a methylotrophic bacterium. mxaF, the gene encoding the large subunit of a methanol dehydrogenase, was cloned from Methylobacterium sp. MB200 through transposon mutagenesis. Deletion of mxaF gene prevented the strain to grow on methanol, suggesting that mxaF is involved in methanol metabolism. Overexpression of mxaF gene in the strain MB200 resulted in a fivefold increase in methanol dehydrogenase activity compared to the wild‐type. Resting cell assays showed that the recombinant strain accumulated 6·6 mg ml−1 L‐serine in 72 h with 30 mg ml−1 wet cells from 50 mg ml−1 glycine and 50 mg ml−1 methanol, representing a 1·5‐fold increment for L‐serine production in contrast to the wild‐type strain. These results demonstrate that the potential for improving the production of L‐serine can be achieved by overexpressing mxaF gene in methylotrophic bacteria.Significance and Impact of the StudyThe amount of L‐serine produced each year worldwide is relatively small compared with the amounts of the other amino acids and hence it is in great demand. Here, we describe a metabolic engineering approach to increase the production of L‐serine in a methylotrophic bacterium Methylobacterium sp. MB200. The result demonstrates that raising the output of L‐serine can be achieved by overexpressing mxaF gene in methylotrophic bacteria.
研究领域:
微生物学
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生物技术
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代谢工程
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PubMed
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
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2024
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IF 3.1
Qiao Xi,Jiang Mengna,Zhu Enze,Gu Yiwen,Chen Zhuoran,Ju Xin,Li Liangzhi,Zhong Xia,Chen Zhi
Chitin, a natural organic compound with content slightly lower than cellulose, is also known for chitosan, a substance derived from chitin through deacetylation. In this experiment, preliminary screening was conducted using the plate discoloration circle method, leading to the selection of a high-yield CDA-producing strain from 28 candidates through rescreening. Morphological characteristics and 16S rDNA sequence analysis revealed 99.93% homology with Enterobacter sichuanensis strain N24, thus naming this strain Enterobacter strain ZCDA27. Initial fermentation of the strain yielded CDA activity of 9.29 U/mL. Single-factor optimization was then performed, followed by a PB test to screen for significant factors affecting enzyme production. The response surface method was used to further optimize the fermentation conditions. The optimal fermentation conditions for the carbon source, nitrogen source, metal ion, fermentation temperature, time, liquid volume, and initial pH were explored. Significant factors affecting enzyme production, including MgSO 4 , initial medium pH, and fructose levels, were identified using the PB test. Finally, the fermentation conditions of ZCDA27 were optimized using the Box-Behnken design combined with RSM, which comprised fructose at 1.020%, magnesium sulfate at 0.016%, and peptone at 1%. The fermentation conditions included a temperature of 37, initial pH of 7.1, rotation speed of 140 × g , fermentation time of 28 h, inoculation amount of 2%, and liquid volume of 40%. Under these conditions, the enzyme activity of ZCDA27 reached 14.52 U/mL, a 1.6-fold increase from the pre-optimization levels. In summary, this study provides an experimental foundation for further development and application of Enterobacter spp. ZCDA27 CDA.
研究领域:
微生物学
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生物化学
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酶工程
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PubMed
高影响因子
JOURNAL OF BIOTECHNOLOGY
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2019
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IF 3.163
Xiao-Ling Tang,Nan-Nan Zhang,Guo-Yan Ye,Yu-Guo Zheng
( R )-3-amino-1-butanol is a key intermediate of Dolutegravir for the treatment of HIV/AIDS and its green and efficient biosynthesis has attracted a great deal of attention. Transaminases are currently used as promising biocatalyst for the synthesis of chiral amines. However, many transaminases have ( S )-specificity and ( R )-selective transaminases were less exploited and studied, making the production of ( R )-amines remain challenging. In this study, a novel transaminase from Actinobacteria sp. ( As -TA) was obtained and applied for the biosynthesis of ( R )-3-amino-1-butanol by transferring the amino group from isopropylamine to 4-hydroxy-2-butanone. After optimization of the reaction condition and using a substrate fed-batch strategy, the conversion of 100, 200, 300, 400 and 500 mM 4-hydroxy-2-butanone reached 100%, 94.9%, 86.1%, 76.1% and 70.9%, respectively. ( R )-3-amino-1-butanol with a maximum yield of 29.6 g/L and 99.9% e.e. value was obtained. This was the first time demonstrating the successful biosynthesis of ( R )-3-amino-1-butanol with transaminase as biocatalyst and the obtained As -TA enriched the enzyme pool of transaminase with ( R )-specificity.
研究领域:
生物化学
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酶工程
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药物合成
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PubMed
高影响因子
Frontiers in Microbiology
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2023
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IF 5.2
Shikai Zhang,Qing Xu,Changbo Ji,Xiaoyu Han,Yang Zhou,Chao Liang,Linran Ma,Weijian Sun,Yanling Li,Zhengyou Yang,Fengchun Zhao,Yuan Tian
Small molecule-induced fermentation of the endophytic fungus Diaporthe sp. AC1 originated from Artemisia argyi was executed to investigate its secondary metabolites. It was fermented in a culture medium containing 5-hydroxytryptophan (5-HTP), 1-methyl-L-tryptophan (1-MT), and tryptamine (TA), respectively. The antibacterial activities of crude extracts against pathogenic bacteria and pathogenic fungi were determined by using the Oxford cup method, while the cytotoxicity of crude extracts against cancer cells was determined by using the MTT method. The results showed that the secondary metabolites of Diaporthe sp. AC1 induced by 1-MT exhibited optimal antibacterial activity and tumor cytotoxicity. The induction conditions of 1-MT were optimized, and the antibacterial activities and tumor cytotoxicity of crude extracts under different induction conditions were investigated. As indicated, the optimal moment for 1-MT addition was before inoculation and its optimal concentration was 0.25 mM. Under these conditions, Diaporthe sp. AC1 was fermented and approximately 12 g of crude extracts was obtained. The crude extracts were then separated and purified to acquire nine monomer compounds, including three new compounds ( 1 – 3 ) and six known compounds ( 4 – 9 ). The antibacterial activities of the compounds against pathogenic bacteria and pathogenic fungi were investigated by using the microdilution method, while their cytotoxicity against cancer cells was analyzed by using the MTT method. The results demonstrated that Compound 1 exhibited moderate antibacterial activities against Verticillium dahlia , Fusarium graminearum, and Botrytis cinerea , as well as a low inhibitory activity against Listeria monocytogenes . Nevertheless, Compound 1 showed significant cytotoxicity against five cancer cells, with IC 50 ranging from 12.26 to 52.52 μM. Compounds 2 and 3 exhibited negligible biological activity, while other compounds showed detectable inhibitory activities against pathogenic bacteria and cancer cells.
研究领域:
微生物学
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药理学
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植物化学
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PubMed
高影响因子
Royal Society Open Science
·
2020
·Vol. 7
·期 9
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IF 2.646
Siqi Liu,Xiaolin Xu,Yanshun Kang,Yingtian Xiao,Huan Liu
Ligninolytic enzymes, including laccase (Lac), manganese peroxidase (MnP) and lignin peroxidase (LiP), have attracted much attention in the degradation of contaminants. Genes of Lac (1827 bp), MnP (1134 bp) and LiP (1119 bp) were cloned from Aspergillus sp. TS-A, and the recombinant Lac (69 kDa), MnP (45 kDa) and LiP (35 kDa) were secretory expressed in Pichia pastoris GS115, with enzyme activities of 34, 135.12 and 103.13 U l−1, respectively. Dyes of different structures were treated via the recombinant ligninolytic enzymes under the optimal degradation conditions, and the result showed that the decolourization rate of Lac on Congo red (CR) in 5 s was 45.5%. Fourier-transform infrared spectroscopy, gas chromatography–mass spectrometry analysis and toxicity tests further proved that the ligninolytic enzymes could destroy the dyes, both those with one or more azo bonds, and the degradation products were non-toxic. Moreover, the combined ligninolytic enzymes could degrade CR more completely compared with the individual enzyme. Remarkably, besides azo dyes, ligninolytic enzymes could also degrade triphenylmethane and anthracene dyes. This suggests that ligninolytic enzymes from Aspergillus sp. TS-A have the potential for application in the treatment of contaminants.
研究领域:
环境科学
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生物技术
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微生物学
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PubMed
高影响因子
Water
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2023
·Vol. 15
·期 20
·3544
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IF 3.4
Qingnan Sun,Xiaoping Zhang,Xin Zhang
In the treatment of wastewater containing only chemical oxygen demand (COD) byChlorellasp., the cell activity and proliferation ability ofChlorellasp. decreased with the culture time, which affected the removal of COD in wastewater. To solve these problems, theChlorellasp.–natural microorganism symbiosis system was prepared. The system was used to explore how natural microorganisms affect the cell activity and the proliferation ability ofChlorellasp. in wastewater. In the treatment of COD byChlorellasp., the removal rate of COD decreased from 45.47% to 28.88%, with a decrease in the cell activity and proliferation ability ofChlorellasp. In theChlorellasp.–natural microorganism symbiotic system, the removal rate of COD reached 45.75%. With the introduction of natural microorganisms, the circulation of CO2and O2betweenChlorellasp. and natural microorganisms promoted photosynthesis and respiration, which enhanced the cell activity ofChlorellasp. Under the condition that the dosage of natural microorganisms was between 1% and 6%, the concentration ofChlorellasp. was close to the logarithmic growth phase, which maintained the proliferation ability ofChlorellasp. At the same time, the natural microorganisms grew and proliferated in wastewater containing only COD through preying onChlorellasp.Keywords:Chlorellasp.;natural microorganisms;symbiosis system;cell activity;predation
研究领域:
环境生物学
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废水处理
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DOI
高影响因子
危险品化学品经营许可证（带存储）