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da Cruz Nizer WS, Adams ME, Montgomery MC, Allison KN, Beaulieu C, Overhage J. Genetic determinants of increased sodium hypochlorite and ciprofloxacin susceptibility in Pseudomonas aeruginosa PA14 biofilms. BIOFOULING 2024; 40:563-579. [PMID: 39189148 DOI: 10.1080/08927014.2024.2395378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 06/12/2024] [Accepted: 08/15/2024] [Indexed: 08/28/2024]
Abstract
Reactive chlorine species (RCS) like sodium hypochlorite (NaOCl) are potent oxidizing agents and widely used biocides in surface disinfection, water treatment, and biofilm elimination. Moreover, RCS are also produced by the human immune system to kill invading pathogens. However, bacteria have developed mechanisms to survive the damage caused by RCS. Using the comprehensive Pseudomonas aeruginosa PA14 transposon mutant library in a genetic screen, we identified a total of 28 P. aeruginosa PA14 mutants whose biofilms showed increased susceptibility to NaOCl in comparison to PA14 WT biofilms. Of these, ten PA14 mutants with a disrupted apaH, PA0793, acsA, PA1506, PA1547, PA3728, yajC, queA, PA3869, or PA14_32840 gene presented a 4-fold increase in NaOCl susceptibility compared to wild-type biofilms. While none of these mutants showed a defect in biofilm formation or attenuated susceptibility of biofilms toward the oxidant hydrogen peroxide (H2O2), all but PA14_32840 also exhibited a 2-4-fold increase in susceptibility toward the antibiotic ciprofloxacin. Further analyses revealed attenuated levels of intracellular ROS and catalase activity only for the apaH and PA1547 mutant, providing insights into the oxidative stress response in P. aeruginosa biofilms. The findings of this paper highlight the complexity of biofilm resistance and the intricate interplay between different mechanisms to survive oxidative stress. Understanding resistance strategies adopted by biofilms is crucial for developing more effective ways to fight resistant bacteria, ultimately contributing to better management of bacterial growth and resistance in clinical and environmental settings.
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Affiliation(s)
| | | | | | | | - Carole Beaulieu
- Department of Health Sciences, Carleton University, Ottawa, Canada
| | - Joerg Overhage
- Department of Health Sciences, Carleton University, Ottawa, Canada
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2
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Drouin P, da Silva ÉB, Tremblay J, Chevaux E, Apper E, Castex M. Inoculation with Lentilactobacillus buchneri alone or in combination with Lentilactobacillus hilgardii modifies gene expression, fermentation profile, and starch digestibility in high-moisture corn. Front Microbiol 2023; 14:1253588. [PMID: 37901805 PMCID: PMC10602787 DOI: 10.3389/fmicb.2023.1253588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 09/25/2023] [Indexed: 10/31/2023] Open
Abstract
Inoculants combining Lentilactobacillus buchneri and Lentilactobacillus hilgardii have been shown to improve the aerobic stability of high-moisture corn (HMC) and whole-plant corn silage, but the mode of action of this co-inoculation remains to be elucidated. This study used metatranscriptomics to evaluate the effects of inoculation with L. buchneri alone or combined with L. hilgardii on the bacterial community, gene expression, fermentation profile, and starch digestibility in HMC. High-moisture corn not inoculated (Control) or inoculated with L. buchneri NCIMB 40788 (LB) or L. buchneri NCIMB 40788 combined with L. hilgardii CNCM-I-4785 (Combo) was ensiled in mini silo bags for 30, 60, 120, and 180 days. The fermentation profile was evaluated at all time points. Metatranscriptomics was performed on samples collected on day 120. Combo had a greater alpha diversity richness index of contigs than LB and Control, and inoculation with Combo and LB modified the beta-diversity of contigs compared to Control. Out of 69 genes of interest, 20 were differentially expressed in LB compared to Control and 25 in Combo compared to Control. Of those differently expressed genes, 16 (10 of which were associated with carbohydrate metabolism and six with amino acid metabolism) were differently expressed in both LB and Combo compared to Control, and all those genes were upregulated in the inoculated silages. When we compared Combo and LB, we found seven genes expressed differently, four associated with carbohydrate metabolism and downregulated in Combo, and three associated with amino acid metabolism and upregulated in Combo. At day 120, the inoculated silages had more culturable lactic acid bacteria, higher Lactobacillus relative abundance, and lower Leuconostoc relative abundance than Control. The concentration of acetic acid remained low throughout ensiling in Control, but in LB and Combo, it increased up to day 60 and remained stable from day 60 to 180. The 1,2-propanediol was only detected in LB and Combo. Inoculation did not affect the concentration of starch, but starch digestibility was greater in Combo than in Control. Inoculation of HMC with Combo modified the gene expression and fermentation profile compared to Control and LB, improving starch digestibility compared to uninoculated HMC.
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Affiliation(s)
- Pascal Drouin
- Independent Researcher, Saint-Jean-sur-Richelieu, QC, Canada
| | | | - Julien Tremblay
- Energy, Mining, and Environment, National Research Council of Canada, Montréal, QC, Canada
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Liao W, Khan I, Huang G, Chen S, Liu L, Leong WK, Li XA, Wu J, Wendy Hsiao WL. Bifidobacterium animalis: the missing link for the cancer-preventive effect of Gynostemma pentaphyllum. Gut Microbes 2022; 13:1847629. [PMID: 33228450 PMCID: PMC8381792 DOI: 10.1080/19490976.2020.1847629] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Colorectal cancer (CRC) ranks the third most common cancer type in both men and women. Besides the known genetic and epigenetic changes in the gut epithelial cells, we now know that disturbed gut microbes could also contribute to the onset and progression of CRC. Hence, keeping a balanced gut microbiota (GM) has become a novel pursue in the medical field, particularly in the area of gastrointestinal disorders. Gynostemma pentaphyllum (Gp) is a dietary herbal medicine. In our previous study, Gp saponins (GpS) displayed prebiotic and cancer-preventive properties through the modulation of GM in ApcMin/+ mice. However, the specific group(s) of GM links to the health effects of GpS remains unknown. To track down the missing link, we first investigated and found that inoculation with fecal materials from GpS-treated ApcMin/+ mice effectively reduces polyps in ApcMin/+ mice. From the same source of the fecal sample, we successfully isolated 16 bacterial species. Out of the 16 bacteria, Bifidobacterium animalis stands out as the responder to the GpS-growth stimulus. Biochemical and RNAseq analysis demonstrated that GpS enhanced expressions of a wide range of genes encoding biogenesis and metabolic pathways in B. animalis culture. Moreover, we found that colonization of B. animalis markedly reduces the polyp burden in ApcMin/+ mice. These findings reveal a mutualistic interaction between the prebiotic and a probiotic to achieve anticancer and cancer-preventive activities. Our result, for the first time, unveils the anticancer function of B. animalis and extend the probiotic horizon of B. animalis.
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Affiliation(s)
- Weilin Liao
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau SAR
| | - Imran Khan
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau SAR
| | - Guoxin Huang
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau SAR
| | - Shengshuang Chen
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau SAR
| | - Liang Liu
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau SAR
| | - Wai Kit Leong
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau SAR
| | - Xiao Ang Li
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau SAR
| | - Jianlin Wu
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau SAR
| | - W. L. Wendy Hsiao
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau SAR,CONTACT W. L. Wendy Hsiao State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau SAR
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Park HJ, Seong HJ, Lee J, Heo L, Sul WJ, Han SW. Two DNA Methyltransferases for Site-Specific 6mA and 5mC DNA Modification in Xanthomonas euvesicatoria. FRONTIERS IN PLANT SCIENCE 2021; 12:621466. [PMID: 33841456 PMCID: PMC8025778 DOI: 10.3389/fpls.2021.621466] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 02/25/2021] [Indexed: 05/08/2023]
Abstract
Xanthomonas euvesicatoria (Xe) is a gram-negative phytopathogenic bacterium that causes bacterial spot disease in tomato/pepper leading to economic losses in plantations. DNA methyltransferases (MTases) are critical for the survival of prokaryotes; however, their functions in phytopathogenic bacteria remain unclear. In this study, we characterized the functions of two putative DNA MTases, XvDMT1 and XvDMT2, in Xe by generating XvDMT1- and XvDMT2-overexpressing strains, Xe(XvDMT1) and Xe(XvDMT2), respectively. Virulence of Xe(XvDMT2), but not Xe(XvDMT1), on tomato was dramatically reduced. To postulate the biological processes involving XvDMTs, we performed a label-free shotgun comparative proteomic analysis, and results suggest that XvDMT1 and XvDMT2 have distinct roles in Xe. We further characterized the functions of XvDMTs using diverse phenotypic assays. Notably, both Xe(XvDMT1) and Xe(XvDMT2) showed growth retardation in the presence of sucrose and fructose as the sole carbon source, with Xe(XvDMT2) being the most severely affected. In addition, biofilm formation and production of exopolysaccharides were declined in Xe(XvDMT2), but not Xe(XvDMT1). Xe(XvDMT2) was more tolerant to EtOH than Xe(XvDMT1), which had enhanced tolerance to sorbitol but decreased tolerance to polymyxin B. Using single-molecule real-time sequencing and methylation-sensitive restriction enzymes, we successfully predicted putative motifs methylated by XvDMT1 and XvDMT2, which are previously uncharacterized 6mA and 5mC DNA MTases, respectively. This study provided new insights into the biological functions of DNA MTases in prokaryotic organisms.
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Affiliation(s)
- Hye-Jee Park
- Department of Plant Science and Technology, Chung-Ang University, Anseong, South Korea
- R and D Innovation Center, Seoul Clinical Laboratories, Yongin, South Korea
| | - Hoon Je Seong
- Department of Systems Biotechnology, Chung-Ang University, Anseong, South Korea
| | - Jongchan Lee
- Department of Plant Science and Technology, Chung-Ang University, Anseong, South Korea
| | - Lynn Heo
- Department of Plant Science and Technology, Chung-Ang University, Anseong, South Korea
| | - Woo Jun Sul
- Department of Systems Biotechnology, Chung-Ang University, Anseong, South Korea
| | - Sang-Wook Han
- Department of Plant Science and Technology, Chung-Ang University, Anseong, South Korea
- *Correspondence: Sang-Wook Han
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Ethanol tolerance assessment in recombinant E. coli of ethanol responsive genes from Lactobacillus buchneri NRRL B-30929. World J Microbiol Biotechnol 2020; 36:179. [PMID: 33155123 DOI: 10.1007/s11274-020-02953-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 10/23/2020] [Indexed: 01/24/2023]
Abstract
We previously identified specific proteins associated with ethanol stress response in a Lactobacillus buchneri strain capable of growing in 10% ethanol. In the current study, the exceptional roles of ethanol responsive genes are examined to determine if they can increase ethanol tolerance in E. coli host cells. The recombinant strains carrying ethanol responsive genes were subjected to growth analyses in media with and without 4% ethanol. Among the expression of these genes and growth analyses of the recombinant strains in ethanol, six genes Lbuc_0522 (NADPH-dependent methylglyoxal reductase), Lbuc_0354 (succinate semialdehyde dehydrogenase), Lbuc_1211(threonyl_tRNA synthetase), Lbuc_2051 (nitroreductase), Lbuc_0707 (branched chain amino acid aminotransferase) and Lbuc_1852 (proline-specific peptidase) conferred host cells tolerance to 4% ethanol. Six genes Lbuc_1523 (phage major capsid protein, HK 97 family), Lbuc_1319 (phosphoglycerate kinase), Lbuc_0787 encoding fumarylacetoacetate hydrolase, Lbuc_1219 encoding UDP-N-acetylmuramate-L-alanine ligase, Lbuc_0466 encoding ornithine carbamoyltransferase and Lbuc_0858 encoding glycine hydroxymethyltransferase showed no impact on growth in media with 4% ethanol with IPTG induction when compared with E. coli carrying control pET28b plasmid. The expression of two genes Lbuc_1557 (S-layer glycoprotein) and Lbuc_2157 (6-phosphogluconate dehydrogenase) resulted ethanol sensitivity phenotype.
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Liang L, Liu R, Freed EF, Eckert CA. Synthetic Biology and Metabolic Engineering Employing Escherichia coli for C2-C6 Bioalcohol Production. Front Bioeng Biotechnol 2020; 8:710. [PMID: 32719784 PMCID: PMC7347752 DOI: 10.3389/fbioe.2020.00710] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/08/2020] [Indexed: 12/18/2022] Open
Abstract
Biofuel production from renewable and sustainable resources is playing an increasingly important role within the fuel industry. Among biofuels, bioethanol has been most widely used as an additive for gasoline. Higher alcohols can be blended at a higher volume compared to ethanol and generate lower greenhouse gas (GHG) emissions without a need to change current fuel infrastructures. Thus, these fuels have the potential to replace fossil fuels in support of more environmentally friendly processes. This review summarizes the efforts to enhance bioalcohol production in engineered Escherichia coli over the last 5 years and analyzes the current challenges for increasing productivities for industrial applications.
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Affiliation(s)
- Liya Liang
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO, United States
| | - Rongming Liu
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO, United States
| | - Emily F. Freed
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO, United States
| | - Carrie A. Eckert
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO, United States
- National Renewable Energy Laboratory, Golden, CO, United States
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Illikoud N, Gohier R, Werner D, Barrachina C, Roche D, Jaffrès E, Zagorec M. Transcriptome and Volatilome Analysis During Growth of Brochothrix thermosphacta in Food: Role of Food Substrate and Strain Specificity for the Expression of Spoilage Functions. Front Microbiol 2019; 10:2527. [PMID: 31781057 PMCID: PMC6856214 DOI: 10.3389/fmicb.2019.02527] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 10/21/2019] [Indexed: 11/13/2022] Open
Abstract
Brochothrix thermosphacta is one of the main spoilers in food, responsible for meat and seafood spoilage through the production of malodorous volatile organic compounds. The molecules produced by this bacterium depend on the substrate (meat or seafood) and the storage conditions such as gas mixtures used in the packaging. It seems also that the spoilage potential is strain dependent as production of diacetyl and acetoin, two molecules responsible for seafood spoilage, varies with strains. Therefore, this suggests the involvement of different metabolic functions depending on both food substrate and strain capacities. In this study, we selected two strains with different abilities to produce diacetyl and acetoin and compared their behavior after grown in beef or cooked peeled shrimp juices. We determined the genes upregulated by both strains depending on the growth substrate and those that were specifically upregulated in only one strain. The genes upregulated by both strains in meat or in shrimp juice revealed the importance of the substrate for inducing specific metabolic pathways. The examination of genes that were specifically upregulated in only one of the two strains revealed strain features associated to specific substrates and also strain-specific regulations of metabolic pathways putatively leading to different levels of spoilage molecule production. This shows that the spoilage potential of B. thermosphacta depends on nutrients provided by food substrate and on metabolic activity potential that each strain possesses.
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Affiliation(s)
| | | | | | - Célia Barrachina
- MGX, CNRS, INSERM, University of Montpellier, Montpellier, France
| | - David Roche
- Génomique Métabolique, Génoscope, Institut François Jacob, CEA, CNRS, Université d'Evry, Université Paris-Saclay, Evry, France
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Liu S, Skory C, Liang X, Mills D, Qureshi N. Increased ethanol tolerance associated with the pntAB locus of Oenococcus oeni and Lactobacillus buchneri. J Ind Microbiol Biotechnol 2019; 46:1547-1556. [PMID: 31289974 DOI: 10.1007/s10295-019-02209-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 06/21/2019] [Indexed: 10/26/2022]
Abstract
Lactobacillus buchneri and Oenococcus oeni are two unique ethanol-tolerant Gram-positive bacteria species. Genome comparison analyses revealed that L. buchneri and O. oeni possess a pntAB locus that was absent in almost all other lactic acid bacteria (LAB) genomes. Our hypothesis is that the pntAB locus contributes to the ethanol tolerance trait of these two distinct ethanol-tolerant organisms. The pntAB locus, consisting of the pntA and pntB genes, codes for NADP(H) transhydrogenase subunits. This membrane-bound transhydrogenase catalyzes the reduction of NADP+ and is known as an important enzyme in maintaining cellular redox balance. In this study, the transhydrogenase operon from L. buchneri NRRL B-30929 and O. oeni PSU-1 were cloned and analyzed. The LbpntB shared 71.0% identity with the O. oeni (OopntB). The entire pntAB locus was expressed in Lactococcus lactis ssp. lactis IL1403 resulting in an increased tolerance to ethanol (6%), butanol (1.8%) and isopropanol (1.8%) when compared to the control strain. However, the recombinant E. coli cells carrying the entire pntAB locus did not show any improved ethanol tolerance. Independent expression of OopntB and LbpntB in recombinant E. coli BL21(DE3)pLysS host demonstrated higher tolerance to ethanol when compared with a control E. coli BL21(DE3)pLysS strain carrying pET28b vector. Ethanol tolerance comparison of E. coli strains carrying LbpntB and OopntB showed that LbpntB conferred higher ethanol tolerance (4.5%) and resulted in greater biomass, while the OopntB conferred lower ethanol tolerance (4.0%) resulted lower biomass. Therefore, the pntB gene from L. buchneri is a better choice in generating higher ethanol tolerance. This is the first study to uncover the role of pntAB locus on ethanol tolerance.
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Gómez-Gómez B, Pérez-Corona T, Mozzi F, Pescuma M, Madrid Y. Silac-based quantitative proteomic analysis of Lactobacillus reuteri CRL 1101 response to the presence of selenite and selenium nanoparticles. J Proteomics 2019; 195:53-65. [DOI: 10.1016/j.jprot.2018.12.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/29/2018] [Accepted: 12/25/2018] [Indexed: 12/20/2022]
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Guo L, Huang L, Su Y, Qin Y, Zhao L, Yan Q. secA, secD, secF, yajC, and yidC contribute to the adhesion regulation of Vibrio alginolyticus. Microbiologyopen 2017; 7:e00551. [PMID: 29057613 PMCID: PMC5911994 DOI: 10.1002/mbo3.551] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 08/26/2017] [Accepted: 09/18/2017] [Indexed: 11/30/2022] Open
Abstract
Vibrio alginolyticus caused great losses to aquaculture. Adhesion is an important virulence factor of V. alginolyticus. In this study, the relationship between V. alginolyticus adhesion and type II secretion system genes (secA, secD, secF, yajC, and yidC) was determined using gene silencing, qRT‐PCR and in vitro adhesion assay. The results showed that the expression of target genes and the bacterial adhesion exhibited significant decreases after transient gene silencing and stable gene silencing, which indicated that secA, secD, secF, yajC, and yidC played roles in the bacterial adhesion of V. alginolyticus. The expression of secA, secD, secF, yajC, and yidC were significantly influenced by temperature, salinity, pH and starvation. The results indicated that the expression of secA, secD, secF, yajC, and yidC were sensitive to different environmental factors, whereas environmental factors can affect V. alginolyticus adhesion via the expression of secA, secD, secF, yajC, and yidC.
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Affiliation(s)
- Lina Guo
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, China
| | - Lixing Huang
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, China
| | - Yongquan Su
- State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, China.,College of Ocean & Earth Sciences, Xiamen University, Xiamen, Fujian, China
| | - Yingxue Qin
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, China
| | - Lingmin Zhao
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, China
| | - Qingpi Yan
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, China.,State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, China
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Heinl S, Grabherr R. Systems biology of robustness and flexibility: Lactobacillus buchneri —A show case. J Biotechnol 2017; 257:61-69. [DOI: 10.1016/j.jbiotec.2017.01.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 01/19/2017] [Accepted: 01/24/2017] [Indexed: 12/25/2022]
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12
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Xu Z, He H, Zhang S, Guo T, Kong J. Characterization of Feruloyl Esterases Produced by the Four Lactobacillus Species: L. amylovorus, L. acidophilus, L. farciminis and L. fermentum, Isolated from Ensiled Corn Stover. Front Microbiol 2017. [PMID: 28626449 PMCID: PMC5454770 DOI: 10.3389/fmicb.2017.00941] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Lactic acid bacteria (LAB) play important roles in silage fermentation, which depends on the production of sufficient organic acids to inhibit the growth of undesirable microorganisms. However, LAB are not able to degrade cellulose and hemicellulose. Bacteria and fibrolytic enzymes are usually used as inoculants to improve the silage quality and digestibility. In the present study, we isolated four Lactobacillus strains (L. amylovorus CGMCC 11056, L. acidophilus CCTCC AB2010208, L. farciminis CCTCC AB2016237 and L. fermentum CCTCC AB2010204) with feruloyl esterase (FAE) activities from ensiled corn stover (CS) by a plate screening assay. The genes encoding FAEs were cloned and hetero-expressed in Escherichia coli. The optimal temperature and pH of these purified enzymes ranged from 45 to 50°C and from 7.0 to 8.0, respectively. They could hydrolyze hydroxycinnamoyl esters in a substrate-specific manner when methyl ferulate, methyl caffeate, methyl ρ-coumarate and methyl sinapinate were used as substrates. Moreover, these four FAEs were able to hydrolyze CS to release hydroxycinnamic acids. Furthermore, these strains could degrade hydroxycinnamic esters, and L. amylovorus CGMCC 11056 was the most efficient strain among these four isolates. These results provided a new target for the development of inoculants to improve silage quality and digestibility.
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Affiliation(s)
- Zhenshang Xu
- State Key Laboratory of Microbial Technology, Shandong UniversityJinan, China
| | - Huiying He
- State Key Laboratory of Microbial Technology, Shandong UniversityJinan, China
| | - Susu Zhang
- State Key Laboratory of Microbial Technology, Shandong UniversityJinan, China
| | - Tingting Guo
- State Key Laboratory of Microbial Technology, Shandong UniversityJinan, China
| | - Jian Kong
- State Key Laboratory of Microbial Technology, Shandong UniversityJinan, China
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13
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Pando JM, Pfeltz RF, Cuaron JA, Nagarajan V, Mishra MN, Torres NJ, Elasri MO, Wilkinson BJ, Gustafson JE. Ethanol-induced stress response of Staphylococcus aureus. Can J Microbiol 2017; 63:745-757. [PMID: 28521110 DOI: 10.1139/cjm-2017-0221] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Transcriptional profiles of 2 unrelated clinical methicillin-resistant Staphylococcus aureus (MRSA) isolates were analyzed following 10% (v/v) ethanol challenge (15 min), which arrested growth but did not reduce viability. Ethanol-induced stress (EIS) resulted in differential gene expression of 1091 genes, 600 common to both strains, of which 291 were upregulated. With the exception of the downregulation of genes involved with osmotic stress functions, EIS resulted in the upregulation of genes that contribute to stress response networks, notably those altered by oxidative stress, protein quality control in general, and heat shock in particular. In addition, genes involved with transcription, translation, and nucleotide biosynthesis were downregulated. relP, which encodes a small alarmone synthetase (RelP), was highly upregulated in both MRSA strains following ethanol challenge, and relP inactivation experiments indicated that this gene contributed to EIS growth arrest. A number of persistence-associated genes were also upregulated during EIS, including those that encode toxin-antitoxin systems. Overall, transcriptional profiling indicated that the MRSA investigated responded to EIS by entering a state of dormancy and by altering the expression of elements from cross protective stress response systems in an effort to protect preexisting proteins.
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Affiliation(s)
- Jasmine M Pando
- a Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA
| | - Richard F Pfeltz
- b BD Diagnostic Systems, Microbiology R&D Department, Sparks, MD 21152, USA
| | - Jesus A Cuaron
- a Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA
| | - Vijayaraj Nagarajan
- c Department of Biological Sciences, University of Southern Mississippi, Hattiesburg, MS 39406, USA
| | - Mukti N Mishra
- d Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Nathanial J Torres
- d Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Mohamed O Elasri
- c Department of Biological Sciences, University of Southern Mississippi, Hattiesburg, MS 39406, USA
| | - Brian J Wilkinson
- e Microbiology Group, School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - John E Gustafson
- a Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA.,d Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK 74078, USA
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