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Microbiology Spectrum Dec 2022sp. is a yellowish Gram-negative bacterium that is usually characterized by high concentrations of sphingophospholipids as lipid components. As microbial enzymes have...
sp. is a yellowish Gram-negative bacterium that is usually characterized by high concentrations of sphingophospholipids as lipid components. As microbial enzymes have been in high demand in industrial fields in the past few decades, this study hopes to provide significant information on lipase activities of sp., since limited studies have been conducted on the sp. lipase. A microbe from one collected Artic soil sample, ARC4, was identified as psychrotolerant sp., and it could grow in temperatures ranging from 0°C to 24°C. The expression of sp. lipase was successfully performed through an efficient approach of utilizing mutated group 3 late embryogenesis abundant (G3LEA) proteins developed from Polypedilum vanderplanki. Purified enzyme was characterized using a few parameters, such as temperature, pH, metal ion cofactors, organic solvents, and detergents. The expressed enzyme is reported to be cold adapted and has the capability to work efficiently under neutral pH (pH 5.0 to 7.0), cofactors like Na ion, and the water-like solvent methanol. Addition of nonionic detergents greatly enhanced the activity of purified enzyme. The mechanism of action of LEA proteins has remained unknown to many; in this study we reveal their presence and improved protein expression due to the molecular shielding effect reported by others. This paper should be regarded as a useful example of using such proteins to influence an existing expression system to produce difficult-to-express proteins.
Topics: Lipase; Sphingobacterium; Detergents; Temperature; Solvents; Peptides; Hydrogen-Ion Concentration; Phylogeny
PubMed: 36314920
DOI: 10.1128/spectrum.01422-21 -
Vavilovskii Zhurnal Genetiki I Selektsii Oct 2022Alkanmonooxygenase enzymes AlkB and Cyp153 are responsible for the aerobic degradation of n-alkanes of petroleum and petroleum products. To prove the usage of n-alkanes...
Alkanmonooxygenase enzymes AlkB and Cyp153 are responsible for the aerobic degradation of n-alkanes of petroleum and petroleum products. To prove the usage of n-alkanes from oil and petroleum products by hydrocarbon-oxidizing bacteria isolated from aviation kerosene TS-1 and automobile gasoline AI-95, the detection of the key genes alkB, Alk1, Alk2, Alk3 and Cyp153 encoding alkanmonooxygenases AlkB and Cyp153 (responsible for the oxidation of hydrocarbons with a certain chain length) was carried out. It was found that bacterial strains isolated from TS-1 jet fuel, except Deinococcus sp. Bi7, had at least one of the studied n-alkane degradation genes. The strains Sphingobacterium multivorum Bi2; Alcaligenes faecalis Bi3; Rhodococcus sp. Bi4; Sphingobacterium sp. Bi5; Rhodococcus erythropolis Bi6 contained the alkB gene. In the strains of hydrocarbon-oxidizing bacteria isolated from gasoline AI- 95, this alkanmonooxygenase gene was not detected. Using the real-time PCR method, the activity of the alkB gene in all bacterial strains isolated from petroleum products was analyzed and the number of its copies was determined. By real-time PCR using a primer with a different sequence of nucleotides to detect the alkB gene, its activity was established in all bacterial strains isolated from gasoline AI-95; besides, the strain Paenibacillus agaridevorans Bi11 was assigned to the group with a high level of its activity (1290 copies/ml). According to the assessment of the growth of isolated hydrocarbon-oxidizing bacteria on a solid Evans mineral medium with the addition of the model mixture of hydrocarbons, the strains were divided into three groups. The distributions of strains of hydrocarbon-oxidizing bacteria in the groups based on the activity of the alkB gene and groups formed based on the growth ability and use of the model mixture of hydrocarbons and petroleum products were found to be consistent. The results obtained indicate that we need to use a complex of molecular and physiological methods for a comprehensive analysis of the distribution of the studied genes in bacteria and to assess their activity in the strains of hydrocarbon-oxidizing bacteria capable of biodegradation of petroleum hydrocarbons.
PubMed: 36313823
DOI: 10.18699/VJGB-22-70 -
Frontiers in Plant Science 2022The dynamics and correlations of chlorophyll and phytol content with silage bacterial of different growth heights were investigated. The results demonstrated that the...
The dynamics and correlations of chlorophyll and phytol content with silage bacterial of different growth heights were investigated. The results demonstrated that the chlorophyll and phytol content of before and after ensiled decreased with the increase of growth height. Ensiling significantly reduced pigment content but had no significant effect on phytol. In addition, pigment yield before and after ensiled increased with growth heights increasing, and the yield at 150 or 180 cm was obviously higher. Moreover, the higher silage quality V-Score were at 150 or 180 cm growth heights. Furthermore, the silage microbial diversity were varied by growth heights, and some specific undesirable microorganisms (, , , etc.) were negatively correlated with pigment and phytol content. Therefore, with comprehensive consideration of pigment, phytol yield, and silage quality, the optimum harvest growth height of was 150 cm. Furthermore, precise reduction of particular undesirable microorganisms maybe helps to preserve pigments and phytol.
PubMed: 36311147
DOI: 10.3389/fpls.2022.996970 -
Food Microbiology Feb 2023Foodborne norovirus (NoV) outbreaks linked to leafy greens are common due to a lack of efficient strategies to prevent NoV spread from contaminated surfaces. We...
Soluble extracellular polymeric substance (SEPS) of histo-blood group antigen (HBGA) expressing bacterium Sphingobacterium sp. SC015 influences the survival and persistence of norovirus on lettuce.
Foodborne norovirus (NoV) outbreaks linked to leafy greens are common due to a lack of efficient strategies to prevent NoV spread from contaminated surfaces. We previously found that Sphingobacterium sp. SC015 in lettuce phyllosphere expresses histo-blood group antigen (HBGA)-like substances in soluble extracellular polymeric substances (SEPS) that contribute to NoV adherence on lettuce. Here, we extracted SEPS from bacterium SC015 (SEPS-SC015), analyzed their chemical composition, and examined their roles in the survival and protection of NoV and surrogates [murine norovirus (MNV-1) and Tulane virus (TuV)] on lettuce. Presence of SEPS-SC015 significantly increased survival and persistence of human NoV (HuNoV), MNV-1, and TuV at days 7 and 14, compared with virus alone. HuNoV, TuV, and MNV-1 seeded with SEPS-SC015 were more resistant to heat (70 °C, 2 min) than these viruses alone. SEPS-SC015 also increased viral resistance to sodium hypochlorite inactivation by treatment with 30 and 300 ppm bleach at 26 °C for 10 min. However, SEPS-SC015 was not effective at protecting these viruses under UV inactivation. Binding of TuV to SC015 bacteria and SEPS-SC015, visualized using transmission electron microscopy, suggests that protection might be related to direct interaction between SEPS-SC015 and viral particles. This study provides important insights that will help inform strategies to improve food safety.
Topics: Humans; Mice; Animals; Norovirus; Lactuca; Blood Group Antigens; Extracellular Polymeric Substance Matrix; Sphingobacterium; Bacteria
PubMed: 36309436
DOI: 10.1016/j.fm.2022.104126 -
World Journal of Microbiology &... Oct 2022Drought severity and duration are expected to increase as a result of ongoing global climate change. Therefore, finding solutions to help plants to deal with drought...
Drought severity and duration are expected to increase as a result of ongoing global climate change. Therefore, finding solutions to help plants to deal with drought stress and to improve growth in the face of limited water resources is critical. In this study, a drought tolerant- plant growth promoting endophytic bacterium was isolated from Aloe vera roots. It was identified as Sphingobacterium changzhouense based on 16S rRNA gene sequencing and was deposited into NCBI database with accession number (ON944028). The effect of S. changzhouense inoculation on maize growth under drought stress was investigated. The results revealed that inoculation significantly (p ≤ 0.05) enhanced root and shoot elongation by 205 and 176.19% respectively. Photosynthesis rate, stomatal conductance and water use efficiency were improved in inoculated plants. interestingly, inoculation resulted in significant increase in total chlorophyll, total carbohydrates, proline, total proteins, total phenolics and total flavonoids by 64, 31.5, 25.1, 75.07, 83.7 and 65.4% respectively. Total antioxidant capacity of inoculated plants (51.2 mg/g FW) was higher than that of non-inoculated plants (11.87 mg/g FW), which was found to be positively correlated to the levels of phenolics and flavonoids. Our finding suggests that S. changzhouense could be used to improve crop growth and assist plants to resist drought stress in arid agricultural lands.
Topics: Droughts; Zea mays; Aloe; RNA, Ribosomal, 16S; Stress, Physiological; Plants; Flavonoids
PubMed: 36306019
DOI: 10.1007/s11274-022-03441-y -
Microorganisms Oct 2022Polyhydroxyalkanoate (PHA), a biodegradable and plastic-like biopolymer, has been receiving research and industrial attention due to severe plastic pollution, resource...
Polyhydroxyalkanoate (PHA), a biodegradable and plastic-like biopolymer, has been receiving research and industrial attention due to severe plastic pollution, resource depletion, and global waste issues. This has spurred the isolation and characterisation of novel PHA-producing strains through cultivation and non-cultivation approaches, with a particular interest in genes encoding PHA synthesis pathways. Since sea sponges and sediment are marine benthic habitats known to be rich in microbial diversity, sponge tissues ( and ) and sediment samples were collected in this study from Redang and Bidong islands located in the Malaysian Coral Triangle region. PHA synthase () genes were identified from sediment-associated bacterial strains using a cultivation approach and from sponge-associated bacterial metagenomes using a non-cultivation approach. In addition, phylogenetic diversity profiling was performed for the sponge-associated bacterial community using 16S ribosomal ribonucleic acid (16S rRNA) amplicon sequencing to screen for the potential presence of PHA-producer taxa. A total of three genes from the bacterial metagenome of and three genes from sediment isolates ( UMTKB-6, UMTKB-7, UMTKB-8) were identified. Produced PHA polymers were shown to be composed of 5C to C monomers, with previously unreported PHA-producing ability of the strain, as well as a 3-hydroxyvalerate-synthesising ability without precursor addition by the strain.
PubMed: 36296332
DOI: 10.3390/microorganisms10102057 -
Journal of Biochemistry Dec 2022Random and rational mutagenesis of an α-amino acid ester acyl transferase from Sphingobacterium siyangensis AJ2458 (SAET) was conducted to examine the production of...
Random and rational mutagenesis of an α-amino acid ester acyl transferase from Sphingobacterium siyangensis AJ2458 (SAET) was conducted to examine the production of aspartame, an α-l-aspartyl-l-phenylalanine methyl ester. We previously reported aspartame production via combination of enzymatic and chemical methods. However, the productivity of the aspartame intermediate by SAET was approximately one-fifth that of l-alanyl-l-glutamine (Ala-Gln), whose production method has already been established. Here, to improve the enzymatic activity of SAET, we performed random mutagenesis in the gene encoding SAET and obtained 10 mutations that elevated the enzymatic activity (1.2- to 1.7-fold increase) relative to that of wild-type SAET. To further improve the activity, we performed mutagenesis to optimize the combination of the obtained mutations and finally selected one SAET variant with 10 amino acid substitutions (M35-4 SAET). An Escherichia coli strain overexpressing M35-4 SAET displayed a 5.7-fold higher activity than that of the wild-type SAET, which was almost equal to that of Ala-Gln by an E. coli strain overexpressing wild-type SAET. The Vmax value of M35-4 SAET was 2.0-fold greater, and its thermostability was higher than those of wild-type SAET. These results suggest that the obtained SAET variants contribute to improvement in aspartame production.
Topics: Acyltransferases; Aspartame; Escherichia coli; Esters; Amino Acids; Mutagenesis
PubMed: 36260086
DOI: 10.1093/jb/mvac083 -
Heliyon Oct 2022Biodegradation is the economically viable solution to restore land contaminated by hazardous pollutants such as benzo(a)pyrene (BaP). The present study focuses on the...
Biodegradation is the economically viable solution to restore land contaminated by hazardous pollutants such as benzo(a)pyrene (BaP). The present study focuses on the biodegradation of benzo(a)pyrene by in contaminated soil. The biodegradation kinetics and bacterial growth were evaluated while the biokinetic model that described the benzo(a)pyrene biodegradation was established. The Monod, Haldane, Powell and Edward models were used to model the bacterial growth in benzo(a)pyrene contaminated soil. Excel template was developed with Fourth order Runga-Kutta numerical algorithm to find the biokinetic parameters of the complex non-linear regression model. An Excel Solver function was used to obtain reasonable best-fit values of kinetic parameters. The Haldane and Edward models are well fit to describe the growth trend and model the kinetics of benzo(a)pyrene biodegradation. Enzyme substrate inhibition is the critical factor that affects the benzo(a)pyrene degradation by which the model defines physically. The results demonstrated that removing benzo(a)pyrene showed positive interaction between substrate inhibition, the concentration of benzo(a)pyrene and sorption of the contaminants on soil particles.
PubMed: 36217485
DOI: 10.1016/j.heliyon.2022.e10799 -
Frontiers in Microbiology 2022Jerusalem artichoke (JA) is a fructan-accumulating crop that has gained popularity in recent years. The objective of the present study was to determine the dynamics of...
Jerusalem artichoke (JA) is a fructan-accumulating crop that has gained popularity in recent years. The objective of the present study was to determine the dynamics of the JA-microbiome during storage. The microbial population on the surface of the JA tuber was determined by next-generation sequencing of 16S rRNA amplicons. Subsequently, the changes in carbohydrate and degree of polymerization of fructan in tubers during storage were measured. Among different genotypes of JA varieties, intergeneric differences were observed in the diversity and abundance of bacterial communities distributed on the surface of tubers. Additionally, bacterial diversity was significantly higher in storage-tolerant varieties relative to the storage-intolerant varieties. Redundancy analysis (RDA) and the correlation matrix indicated a relationship between changes in the carbohydrates and microbial community succession during tuber storage. The tuber decay rate correlated positively with the degree of polymerization of fructan. Moreover, and in perishable varieties correlated significantly with the decay rate. Therefore, the bacteria associated with the decay rate may be involved in the degradation of the degree of polymerization of fructan. Furthermore, showed a significant positive correlation with inulin during storage but a negative correlation with the decay rate, suggesting its antagonistic role against pathogenic bacteria on the surface of JA tubers. However, the above correlation was not observed in the storage-tolerant varieties. Functional annotation analysis revealed that storage-tolerant JA varieties maintain tuber quality through enrichment of biocontrol bacteria, including , , and to resist pathogens. These results suggested that crop genotype and the structural composition of carbohydrates may result in differential selective enrichment effects of microbial communities on the surface of JA varieties. In this study, the relationship between microbial community succession and changes in tuber carbohydrates during JA storage was revealed for the first time through the combination of high-throughput sequencing, high-performance liquid chromatography (HPLC), and high-performance ion-exchange chromatography (HPIC). Overall, the findings of this study are expected to provide new insights into the dynamics of microbial-crop interactions during storage.
PubMed: 36187957
DOI: 10.3389/fmicb.2022.986659 -
Frontiers in Microbiology 2022Root-associated microbial communities are well known for their ability to prime and augment plant defenses that reduce herbivore survival or alter behavior (i.e.,...
Root-associated microbial communities are well known for their ability to prime and augment plant defenses that reduce herbivore survival or alter behavior (i.e., resistance). In contrast, the role root microbes play in plant tolerance to herbivory, an evolutionarily sustainable alternative to resistance, is overlooked. In this study, we aimed to expand our limited understanding of what role rhizosphere microbial communities play in supporting tolerance to insect damage. Using domesticated tomatoes and their wild ancestors ( spp.), we first documented how tobacco hornworm () herbivory impacted tomato fruit production in order to quantify plant tolerance. We then characterized the bacterial and fungal rhizosphere communities harbored by high and low tolerance plants. Wild tomatoes excelled at tolerating hornworm herbivory, experiencing no significant yield loss despite 50% leaf area removal. Their domesticated counterparts, on the other hand, suffered 26% yield losses under hornworm herbivory, indicating low tolerance. Ontogeny (i.e., mid- vs. late-season sampling) explained the most variation in rhizosphere community structure, with tomato line, tolerance, and domestication status also shaping rhizosphere communities. Fungal and bacterial community traits that associated with the high tolerance line include (1) high species richness, (2) relatively stable community composition under herbivory, and (3) the relative abundance of taxa belonging to , , and . Characterizing tolerance-associating microbiomes may open new avenues through which plant defenses are amended in pest management, such as plant breeding efforts that enhance crop recruitment of beneficial microbiomes.
PubMed: 36187948
DOI: 10.3389/fmicb.2022.981987