Isolation and Characterization of a Novel Laccase LacZ1 for Lignin Degradation

2021 ◽  
Author(s):  
Weiran Zhang ◽  
Weiwei Wang ◽  
Jinghong Wang ◽  
Guinan Shen ◽  
Yuan Yuan ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
High Temperature ◽  
Lignin Degradation ◽  
Microbial Consortium ◽  
Organic Polymer ◽  
Lignocellulose Degradation ◽  
Bacterial Laccase ◽  
Isolation And Characterization ◽  
Acid Pathway ◽  
Insight Into

Lignin is a complex natural organic polymer and is one of the primary components of lignocellulose. The efficient utilization of lignocellulose is limited because it is difficult to degrade lignin. In this study, we screened a lacz1 gene fragment encoding laccase from the macro transcriptome data of a microbial consortium WSC-6, which can efficiently degrade lignocellulose. The RT-qPCR results demonstrated that the expression level of the lacz1 gene during the peak period of lignocellulose degradation by WSC-6 increased by 30.63 times compared to the initial degradation period. Phylogenetic tree analysis demonstrated that the complete lacz1 gene is derived from Bacillus sp. and encoded laccase. The corresponding protein LacZ1 was expressed and purified by Ni-chelating affinity chromatography. The optimum temperature was 75°C, the optimum pH was 4.5, and the highest enzyme activity reached 16.39 U/mg. We found that Cu 2+ was an important cofactor needed for LacZ1 to have enzyme activity. The molecular weight distribution of lignin was determined by Gel Permeation Chromatography (GPC) and changes in the lignin structure were determined by 1H Nuclear Magnetic Resonance Spectra (1H NMR). The degradation products of lignin by LacZ1 were determined by Gas Chromatography and Mass Spectrometry (GC-MS), and three lignin degradation pathways (the gentian acid pathway, benzoic acid pathway, and protocatechuic acid pathway) were proposed. This study provides insight into the degradation of lignin and new insights into high-temperature bacterial laccase. IMPORTANCE Lignin is a natural aromatic polymer that is not easily degraded, hindering the efficient use of lignocellulose-rich biomass resources, such as straw. Biodegradation is a method of decomposing lignin that has recently received increasing attention. In this study, we screened a gene encoding laccase from the lignocellulose-degrading microbial consortium WSC-6, purified the corresponding protein LacZ1, characterized the enzymatic properties of laccase LacZ1, and speculated that the degradation pathway of LacZ1 degrades lignin. This study identified a new, high-temperature bacterial laccase that can degrade lignin, providing insight into lignin degradation by this laccase.

scholarly journals Metagenomic insight into lignocellulose degradation of the thermophilic microbial consortium TMC7

2021 ◽  
Author(s):  
Yi Wang ◽  
Chen Wang ◽  
Yonglun Chen ◽  
Beibei Chen ◽  
Peng Guo ◽  
...  
Keyword(s):  
Microbial Consortium ◽  
Lignocellulose Degradation ◽  
Insight Into

scholarly journals Significant Improvement of Straw  Lignocellulose Degradation Rate by Subordination Consortium Composed of Cellulomonas ZJW-6 and Acinetobacter DA-25

2021 ◽  
Author(s):  
Yunpeng Guan ◽  
Hongyu Zhu ◽  
Yuan Zhu ◽  
Longhua Shu ◽  
Hemei Zhao ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Agricultural Development ◽  
Degradation Rate ◽  
High Efficiency ◽  
Microbial Consortium ◽  
Temperature Tolerance ◽  
Degradation Efficiency ◽  
Microbial Consortia ◽  
Lignocellulose Degradation ◽  
Glucosidase Activity

Abstract BackgroundThe effective utilization of lignocellulose is essential for achieving circular economy and sustainable agricultural development. The screening of lignocellulose-degrading strains from the environment and artificial establishment of microbial consortia can achieve better degradation effects. In this paper, microbial consortium 625 was established and screened based on high lignocellulose degradation ability but low β-glucosidase activity of Cellulomonas ZJW-6 to complement enzyme activity and enhance lignocellulose degradation by exerting the subordination effect. This research provides an effective strategy for artificially establishing microbial consortia, improving lignocellulose degradation efficiency, and enhancing bioenergy production.ResultsIn order to establish high-efficiency microbial consortia, Cellulomonas ZJW-6 with low β-glucosidase activity was combined in pairs with 14 strains with high β-glucosidase activity according to the enzyme activity complementation principle, from which microbial consortium 625 composed of strains ZJW-6 and DA-25 was screened, which had significantly enhanced lignocellulose degradation rate compared with purely cultured ZJW-6 strain and other 13 combinations. The single factor test showed that consortium 625 had better pH and temperature tolerance. The lignocellulose degradation rate of this consortium was 57.62% after verification test under optimized conditions using response surface method. The induction test showed that the growth of strain DA-25 was inhibited by strain ZJW-6 and its filtrate, while strain DA-25 and its filtrate promoted the growth of strain ZJW-6 and significantly enhanced the activities of key enzymes in the consortium 625 lignocellulose degrading system, among which the β-Glucosidase activity was significantly higher than that in purely cultured ZJW-6 strain. ConclusionMicrobial consortium 625, composed of Cellulomonas ZJW-6 (dominant strain) and Acinetobacter DA-25, with high lignocellulose degradation efficiency, was screened according to the enzyme activity complementation principle. Interestingly, microbial consortium 625 exhibited complementation in enzyme activities of its two strains, improvement in its tolerance to temperature and pH, and the same effect of DA-25 filtrate as strain DA-25. Based on the previous studies on Acinetobacter, we speculate that a certain compound adverse to the growth of strain DA-25 may be produced during lignocellulose degradation by strain ZJW-6, while secretions of strain DA-25 inhibit this compound leading to an increase in the growth and enzyme activity of strain ZJW-6.

DNA-Polymerases α, δ and ε from T-Cell Spontaneous Lymphoblastic Leukemia of Sprague-Dawley Inbred Rat: Isolation and Characterization

1995 ◽  
Vol 60 (9) ◽  
pp. 1555-1572 ◽  
Author(s):  
Pavel Kramata ◽  
Jaroslav Černý ◽  
Gabriel Birkuš ◽  
Ivan Votruba ◽  
Berta Otová ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Lymphoblastic Leukemia ◽  
Dna Polymerases ◽  
Sedimentation Coefficient ◽  
Nuclear Antigen ◽  
Exonuclease Activity ◽  
Sprague Dawley ◽  
Dna Primase ◽  
Isolation And Characterization ◽  
Inbred Rat

Using a single isolation procedure and selective assays for the determination of enzyme activity, highly purified DNA-polymerases α, δ and ε were isolated from the lymphoma of Sprague-Dawley inbred rats. For pol α the subunit composition was 170, 70, 57 and 53 kDa with sedimentation coefficient 8.7 S for the native molecule; pol delta consists of two polypeptides (133 and 46 kDa; sedimentation coefficient 8.2 S), while pol ε is a single polypeptide (140 kDa) and its sedimentation coefficient is 7.0 S. Comparison of the interaction of individual enzymes with known inhibitors and proliferating cell nuclear antigen (PCNA) using the template-primer poly dA-oligo dT12-18, gave the following data: (i) pol α is selectively inhibited by N2-(p-butylphenyl)-2'-deoxyguanosine 5'-triphosphate (BuPdGTP) and stimulated by dimethyl sulfoxide; (ii) all the enzymes are inhibited by N-ethylmaleimide and aphidicolin; (iii) PCNA stimulates pol δ approximately 50 times while pol ε is moderately inhibited; (iv) pol α exhibits considerably higher DNA-primase activity with poly dC as template than with poly dT, and negligible 3'-5'-exonuclease activity whereas pol δ and pol ε, which do not exert any DNA-primase activity have approximately the same 3'-5'-exonuclease activity. The ability of individual polymerases to utilize poly dT-oligo dA12-18 as a template-primer at different pH values, ionic strengths and Mg2+-concentrations was also investigated. In comparison to poly dA-oligo dT12-18 template-primer, pol α has 140% of enzyme activity on poly dT-oligo dA12-18 under optimal conditions, whereas the activity of pol ε and pol δ is 4 times and 10 times lower, respectively.

scholarly journals Insight into the Metabolic Profiles of Pb(II) Removing Microorganisms

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4008
Author(s):  
Carla Cilliers ◽  
Evans M. N. Chirwa ◽  
Hendrik G. Brink
Keyword(s):  
Liquid Chromatography ◽  
High Performance ◽  
Microbial Consortium ◽  
Luria Bertani ◽  
Nutrient Concentrations ◽  
Batch Experiments ◽  
Metabolic Study ◽  
Luria Bertani Broth ◽  
Tandem Mass Spectroscopy ◽  
Insight Into

The objective of the study was to gather insight into the metabolism of lead-removing microorganisms, coupled with Pb(II) removal, biomass viability and nitrate concentrations for Pb(II) bioremoval using an industrially obtained microbial consortium. The consortium used for study has proven to be highly effective at removing aqueous Pb(II) from solution. Anaerobic batch experiments were conducted with Luria-Bertani broth as rich growth medium over a period of 33 h, comparing a lower concentration of Pb(II) with a higher concentration at two different nutrient concentrations. Metabolite profiling and quantification were conducted with the aid of both liquid chromatography coupled with tandem mass spectroscopy (UPLC-HDMS) in a “non-targeted” fashion and high-performance liquid chromatography (HPLC) in a “targeted” fashion. Four main compounds were identified, and a metabolic study was conducted on each to establish their possible significance for Pb(II) bioremoval. The study investigates the first metabolic profile to date for Pb(II) bioremoval, which in turn can result in a clarified understanding for development on an industrial and microbial level.

Influence of Enzyme Activity of Bacteria and Leucocytes in Raw Milk on Age Gelation after UHT Processing

1984 ◽  
Vol 47 (2) ◽  
pp. 105-107 ◽  
Author(s):  
BARBARA P. KEOGH ◽  
G. PETTINGILL
Keyword(s):  
Enzyme Activity ◽  
High Temperature ◽  
Inhibitory Action ◽  
Raw Milk ◽  
Bacterial Counts ◽  
High Temperature Processing ◽  
The Relationship ◽  
Ultra High Temperature

An investigation was undertaken into the relationship between the enzyme activity of cells harvested from raw milk and time taken for age gelation (TAG) to occur in the milk after ultra-high-temperature processing. It was shown that there was no relationship between the TAG and the bacterial counts on milk agar at 30°C or 7°C nor was there a relationship between the counts and the level of enzyme activity of the harvested cells. There was, however, a significant correlation between the level of enzyme activity of the harvested cells and the TAG. When extra bovine leucocytes were added to raw milk before processing, the TAG was increased. This suggested that there was an inhibitory action of leucocytes in development of age gelation.

scholarly journals Substrate-dependent competition and cooperation relationships between Geobacter and Dehalococcoides for their organohalide respiration

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Yongyi Liang ◽  
Qihong Lu ◽  
Zhiwei Liang ◽  
Xiaokun Liu ◽  
Wenwen Fang ◽  
...  
Keyword(s):  
Electron Donors ◽  
Community Stability ◽  
Organohalide Respiration ◽  
Competition And Cooperation ◽  
Free Competition ◽  
Isolation And Characterization ◽  
Geochemical Cycling ◽  
New Strategy ◽  
Insight Into

AbstractObligate and non-obligate organohalide-respiring bacteria (OHRB) play central roles in the geochemical cycling and environmental bioremediation of organohalides. Their coexistence and interactions may provide functional redundancy and community stability to assure organohalide respiration efficiency but, at the same time, complicate isolation and characterization of specific OHRB. Here, we employed a growth rate/yield tradeoff strategy to enrich and isolate a rare non-obligate tetrachloroethene (PCE)-respiring Geobacter from a Dehalococcoides-predominant microcosm, providing experimental evidence for the rate/yield tradeoff theory in population selection. Surprisingly, further physiological and genomic characterizations, together with co-culture experiments, revealed three unique interactions (i.e., free competition, conditional competition and syntrophic cooperation) between Geobacter and Dehalococcoides for their respiration of PCE and polychlorinated biphenyls (PCBs), depending on both the feeding electron donors (acetate/H2 vs. propionate) and electron acceptors (PCE vs. PCBs). This study provides the first insight into substrate-dependent interactions between obligate and non-obligate OHRB, as well as a new strategy to isolate fastidious microorganisms, for better understanding of the geochemical cycling and bioremediation of organohalides.

A Theoretical Insight into the Curing Mechanism of Phthalonitrile Resins Promoted by Aromatic Amines

2021 ◽  
Author(s):  
Zuowei Chen ◽  
Liquan Wang ◽  
Jiaping Lin ◽  
Lei Du
Keyword(s):  
High Temperature ◽  
Aromatic Amines ◽  
Academic Research ◽  
Engineering Applications ◽  
Wide Range ◽  
Curing Mechanism ◽  
Theoretical Insight ◽  
Insight Into

High-temperature phthalonitrile resins have a wide range of applications, and understanding their curing mechanism is of great importance for academic research and engineering applications. However, the actual curing mechanism is...

scholarly journals Isolation and characterization of bleomycin-resistant clones of CHO cells

1979 ◽  
Vol 34 (3) ◽  
pp. 269-279 ◽  
Author(s):  
Sylvia Brabbs ◽  
J. R. Warr
Keyword(s):  
Enzyme Activity ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Tween 80 ◽  
The Other ◽  
Resistant Clone ◽  
Ovary Cells ◽  
Isolation And Characterization ◽  
Significant Difference

SUMMARYFive clones of Chinese hamster ovary cells with increased resistance to bleomycin have been isolated following ethylmethanesulphonate mutagenesis. Resistance was stable in three of the clones, but unstable in the other two. One of the stably resistant clones was cross resistant to unrelated drugs, and in contrast to the parental cells, its response to bleomycin was potentiated by tween 80. These two observations suggested a membrane alteration in the resistant clone. There was no significant difference in bleomycin-inactivating enzyme activity between the parental and resistant clones.

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