scholarly journals Diversity of Weissella confusa in Pozol and Its Carbohydrate Metabolism

2021 ◽  
Vol 12 ◽  
Author(s):  
Diana Hernández-Oaxaca ◽  
Rafael López-Sánchez ◽  
Luis Lozano ◽  
Carmen Wacher-Rodarte ◽  
Lorenzo Segovia ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Fermentation Process ◽  
Carbon Sources ◽  
Ecological Niches ◽  
Gene Products ◽  
Facultative Anaerobe ◽  
Fermentative Metabolism ◽  
Genomic Analyses ◽  
Carbohydrate Enzymes ◽  
Weissella Confusa

The genus Weissella is composed of a group of Gram-positive facultative anaerobe bacteria with fermentative metabolism. Strains of this genus have been isolated from various ecological niches, including a wide variety of fermented cereal foods. The present study aimed to determine the relative abundance and fermentation capabilities of Weissella species isolated from pozol, a traditional maya product made of lime-cooked (nixtamalized) fermented maize. We sequenced the V3-V4 regions of 16S rDNA; Weissella was detected early in the fermentation process and reached its highest relative abundance (3.89%) after 3 h of culture. In addition, we evaluated five Weissella strains previously isolated from pozol but reported as non-amylolytic, to define alternative carbon sources such as xylan, xylooligosaccharides, and sucrose. While no growth was observed on birch xylan, growth did occur on xylooligosaccharides and sucrose. Strains WcL17 and WCP-3A were selected for genomic sequencing, as the former shows efficient growth on xylooligosaccharides and the latter displays high glycosyltransferase (GTF) activity. Genomes of both strains were assembled and recorded, with a total of 2.3 Mb in 30 contigs for WcL17 and 2.2 Mb in 45 contigs for WCP-3a. Both strains were taxonomically assigned to Weissella confusa and genomic analyses were performed to evaluate the gene products encoding active carbohydrate enzymes (CAZy). Both strains have the gene content needed to metabolize sucrose, hemicellulose, cellulose, and starch residues, all available in pozol. Our results suggest that the range of secondary enzymatic activity in Weissella confusa strains confer them with wide capabilities to participate in fermentative processes of natural products with heterogeneous carbon sources.

scholarly journals Evaluation of bacterial diversity during fermentation process: a comparison between handmade and machine-made high-temperature Daqu of Maotai-flavor liquor

2020 ◽  
Vol 70 (1) ◽  
Author(s):  
Qiancheng Zuo ◽  
Yongguang Huang ◽  
MinGuo
Keyword(s):  
High Temperature ◽  
Bacterial Diversity ◽  
Relative Abundance ◽  
Fermentation Process ◽  
High Throughput Sequencing ◽  
Illumina Miseq ◽  
Functional Bacteria ◽  
Significant Difference ◽  
Fermentation Technology ◽  
Molding Methods

Abstract Purpose High-temperature Daqu is a traditional fermentation starter that is used for Chinese Maotai-flavor Baijiu production. Although the bacteria in high-temperature Daqu are known to be responsible for developing the quality and flavor of Baijiu during the fermentation process, there is little information on the properties of the bacteria during the fermentation of high-temperature Daqu, especially machine-made high-temperature Daqu. This has limited the development of the Maotai-flavor Baijiu industry, particularly with regard to the mechanized production of Maotai-flavor Baijiu. Methods Illumina MiSeq high-throughput sequencing was applied to study bacterial compositions during the fermentation of handmade and machine-made high temperatures. Results The results show that bacterial diversity in machine-made Daqu was similar but higher than that in handmade Daqu at the end of fermentation, and there was no significant difference between the methods with regard to the dominant genera and their dynamic changes during fermentation. Rhizobium, Bacillus, Thermoactinomyces, Weissella, Lactobacillus, and Saccharopolyspora were the dominant genera during the fermentation of both Daqus, although the relative abundance of these dominant genera differed between the two methods. Interestingly, the machine-made Daqu contained a higher relative abundance of Bacillus than handmade Daqu at all fermentation times. Bacillus is the most important functional bacteria in the fermentation of Maotai-flavor Baijiu, suggesting that mechanical-molding methods could be applied to industrial Maotai-flavor Daqu production. Conclusion These results suggest that mechanical-molding methods could be applied to industrial Maotai-flavor Daqu production, which could be helpful for industrial Maotai-flavor Baijiu production and the development of fermentation technology.

scholarly journals Convergent Pathways for Utilization of the Amino Sugars N-Acetylglucosamine,N-Acetylmannosamine, and N-Acetylneuraminic Acid by Escherichia coli

1999 ◽  
Vol 181 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Jacqueline Plumbridge ◽  
Eric Vimr
Keyword(s):  
Escherichia Coli ◽  
Carbon Sources ◽  
Amino Sugars ◽  
Good Growth ◽  
Gene Products ◽  
Phosphotransferase System ◽  
Regulatory Mutation ◽  
Putative Gene ◽  
Acetylneuraminic Acid ◽  
K 12

ABSTRACT N-Acetylglucosamine (GlcNAc) andN-acetylneuraminic acid (NANA) are good carbon sources forEscherichia coli K-12, whereasN-acetylmannosamine (ManNAc) is metabolized very slowly. The isolation of regulatory mutations which enhanced utilization of ManNAc allowed us to elucidate the pathway of its degradation. ManNAc is transported by the manXYZ-encoded phosphoenolpyruvate-dependent phosphotransferase system (PTS) transporter producing intracellular ManNAc-6-P. This phosphorylated hexosamine is subsequently converted to GlcNAc-6-P, which is further metabolized by the nagBA-encoded deacetylase and deaminase of the GlcNAc-6-P degradation pathway. Two independent mutations are necessary for good growth on ManNAc. One mutation maps tomlc, and mutations in this gene are known to enhance the expression of manXYZ. The second regulatory mutation was mapped to the nanAT operon, which encodes the NANA transporter and NANA lyase. The combined action of thenanAT gene products converts extracellular NANA to intracellular ManNAc. The second regulatory mutation defines an open reading frame (ORF), called yhcK, as the gene for the repressor of the nan operon (nanR). Mutations in the repressor enhance expression of the nanAT genes and, presumably, three distal, previously unidentified genes,yhcJIH. Expression of just one of these downstream ORFs,yhcJ, is necessary for growth on ManNAc in the presence of an mlc mutation. The yhcJ gene appears to encode a ManNAc-6-P-to-GlcNAc-6-P epimerase (nanE). Another putative gene in the nan operon, yhcI, likely encodes ManNAc kinase (nanK), which should phosphorylate the ManNAc liberated from NANA by the NanA protein. Use of NANA as carbon source by E. coli also requires thenagBA gene products. The existence of a ManNAc kinase and epimerase within the nan operon allows us to propose that the pathways for dissimilation of the three amino sugars GlcNAc, ManNAc, and NANA, all converge at the step of GlcNAc-6-P.

scholarly journals Exploration of Nitrate Reductase Metabolic Pathway inCorynebacterium pseudotuberculosis

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Sintia Almeida ◽  
Cassiana Sousa ◽  
Vinícius Abreu ◽  
Carlos Diniz ◽  
Elaine M. S. Dorneles ◽  
...  
Keyword(s):  
Electron Transport ◽  
Nitrate Reductase ◽  
Virulence Factors ◽  
Electron Transport Chain ◽  
Drug Targets ◽  
Carbon Sources ◽  
The Other ◽  
Ecological Niches ◽  
Transport Chain ◽  
In Silico Methods

Based on the ability of nitrate reductase synthesis,Corynebacterium pseudotuberculosisis classified into two biovars: Ovis and Equi. Due to the presence of nitrate reductase, the Equi biovar can survive in absence of oxygen. On the other hand, Ovis biovar that does not have nitrate reductase is able to adapt to various ecological niches and can grow on certain carbon sources. Apart from these two biovars, some other strains are also able to carry out the reduction of nitrate. The enzymes that are involved in electron transport chain are also identified by in silico methods. Findings about pathogen metabolism can contribute to the identification of relationship between nitrate reductase and theC. pseudotuberculosispathogenicity, virulence factors, and discovery of drug targets.

Biofilm formation by a biotechnologically important tropical marine yeast isolate, Yarrowia lipolytica NCIM 3589

2008 ◽  
Vol 58 (6) ◽  
pp. 1221-1229 ◽  
Author(s):  
D. H. Dusane ◽  
Y. V. Nancharaiah ◽  
V. P. Venugopalan ◽  
A. R. Kumar ◽  
S. S. Zinjarde
Keyword(s):  
Yarrowia Lipolytica ◽  
Biofilm Formation ◽  
Edible Oils ◽  
Carbon Sources ◽  
Three Dimensional ◽  
Ecological Niches ◽  
Lag Phase ◽  
Biofilm Growth ◽  
Water Media ◽  
Biofilm Development

Biofilm formation by Yarrowia lipolytica, a biotechnologically important fungus in microtitre plates, on glass slide surfaces and in flow cell was investigated. In microtitre plates, there was a short lag phase of adhesion followed by a period of rapid biofilm growth. The fungus formed extensive biofilms on glass slides, whereas in flow-cells a multicellular, three-dimensional microcolony structure was observed. The isolate formed biofilms in seawater and in fresh water media at neutral pH when grown in microtitre plates. The carbon sources differentially affected formation of biofilms in microtitre plates. Lactic acid, erythritol, glycerol, glucose and edible oils supported the formation of biofilms, while alkanes resulted in sub-optimal biofilm development. A variation in the morphology of the fungus was observed with different carbon sources. The results point to the possible existence of highly structured biofilms in varied ecological niches from where the yeast is isolated.

scholarly journals EFFECT OF GROUNDNUT CAKE AND SOYA BEANS ON ENHANCED CITRIC ACID PRODUCTION FROM PAWPAW AND ORANGE PEEL BY MUTANTS OF ASPERGILLUS NIGER

2019 ◽  
Vol 17 (1) ◽  
pp. 147-155
Author(s):  
H. T. BALOGUN-ABIOLA ◽  
S. O. KAREEM ◽  
R. B. AFOLABI ◽  
O. A. AKINLOYE
Keyword(s):  
Citric Acid ◽  
Solid State ◽  
Aspergillus Niger ◽  
Mutant Strain ◽  
Fermentation Process ◽  
Carbon Sources ◽  
Orange Peel ◽  
Nitrogen Sources ◽  
Groundnut Cake ◽  
Mutant Strains

This present study was concerned with the biosynthesis of citric acid (CA) with mutant strain of Aspergillus niger using pawpaw and orange peel as substrates by solid state fermentation process. The A. niger strain isolated from spoilt orange was identified, screened for CA production on Czapek-Dox Agar and subjected to mutation by ethidium bromide. The effect of carbon sources, nitrogen sources and substrates were also determined.  Among the mutant strains, A. niger PJ-02 A120 was found to be the best mutant that produced citric acid (65.00±0.58f) after 48 hours in Vogel’s medium. The effects of carbon sources (sucrose and glucose) on CA production from each substrate (orange and pawpaw peel) using mutant A. niger PJ-02 was determined and sucrose, the best carbon source was combined with two the nitrogen sources (groundnut cake and soyabeans) to determine the most suitable supplement for CA production. Groundnut cake enhances the production of citric acid while soyabeans was inhibitory. Citric acid was further produced in pawpaw peel and orange peel medium containing sucrose (5 %) groundnut cake (2 %), methanol (1.5 %) and the mutant strain. The orange peel substrates yielded 112.07g/kg of CA while 107.17g/kg was recorded for pawpaw peel when fermented for 5 days at 30°C. The Production of citric acid with mutant Aspergillus niger proved better with orange peel than pawpaw peel when optimized with alcohol.      

scholarly journals sal Genes Determining the Catabolism of Salicylate Esters Are Part of a Supraoperonic Cluster of Catabolic Genes in Acinetobacter sp. Strain ADP1

2000 ◽  
Vol 182 (7) ◽  
pp. 2018-2025 ◽  
Author(s):  
Rheinallt M. Jones ◽  
Vassilis Pagmantidis ◽  
Peter A. Williams
Keyword(s):  
Esterase Activity ◽  
Carbon Sources ◽  
Open Reading Frames ◽  
Fatty Acid Transport ◽  
Gene Products ◽  
Hydroxylase Activity ◽  
Cell Extracts ◽  
Catabolic Genes ◽  
Hydrocarbon Transport ◽  
Reading Frames

ABSTRACT A 5-kbp region upstream of the are-ben-cat genes was cloned from Acinetobacter sp. strain ADP1, extending the supraoperonic cluster of catabolic genes to 30 kbp. Four open reading frames, salA, salR, salE, andsalD, were identified from the nucleotide sequence. Reverse transcription-PCR studies suggested that these open reading frames are organized into two convergent transcription units, salARand salDE. The salE gene, encoding a protein of 239 residues, was ligated into expression vector pET5a. Its product, SalE, was shown to have esterase activity against short-chain alkyl esters of 4-nitrophenol but was also able to hydrolyze ethyl salicylate to ethanol and salicylic acid. A mutant of ADP1 with a Kmrcassette introduced into salE had lost the ability to utilize only ethyl and methyl salicylates of the esters tested as sole carbon sources, and no esterase activity against ethyl salicylate could be detected in cell extracts. SalE was induced during growth on ethyl salicylate but not during growth on salicylate itself. salDencoded a protein of undetermined function with homologies to theEscherichia coli FadL membrane protein, which is involved in facilitating fatty acid transport, and a number of other proteins detected during aromatic catabolism, which may also function in hydrocarbon transport or uptake processes. A Kmr cassette insertion in salD deleteriously affected cell growth and viability. The salA and salR gene products closely resemble two Pseudomonas proteins, NahG and NahR, respectively encoding salicylate hydroxylase and the LysR family regulator of both salicylate and naphthalene catabolism.salA was cloned into pUC18 together with salRand salE, and its gene product showed salicylate-inducible hydroxylase activity against a range of substituted salicylates, with the same relative specific activities as found in wild-type ADP1 grown on salicylate. Mutations involving insertion of Kmrcassettes into salA and salR eliminated expression of salicylate hydroxylase activity and the ability to grow on either salicylate or ethyl salicylate. Studies of mutants with disruptions of genes of the β-ketoadipate pathway with or without an additional salE mutation confirmed that ethyl salicylate and salicylate were channeled into the β-ketoadipate pathway at the level of catechol and thence dissimilated by the cat gene products. SalR appeared to regulate expression of salA but not salE.

scholarly journals A key metabolic gene for recurrent freshwater colonization and radiation in fishes

Science ◽  
2019 ◽  
Vol 364 (6443) ◽  
pp. 886-889 ◽  
Author(s):  
Asano Ishikawa ◽  
Naoki Kabeya ◽  
Koki Ikeya ◽  
Ryo Kakioka ◽  
Jennifer N. Cech ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Desaturase ◽  
Ecological Niches ◽  
Desaturase Gene ◽  
Genomic Analyses ◽  
Freshwater Habitats ◽  
Adaptive Radiations ◽  
Close Relatives ◽  
Transgenic Manipulation ◽  
Do So

Colonization of new ecological niches has triggered large adaptive radiations. Although some lineages have made use of such opportunities, not all do so. The factors causing this variation among lineages are largely unknown. Here, we show that deficiency in docosahexaenoic acid (DHA), an essential ω-3 fatty acid, can constrain freshwater colonization by marine fishes. Our genomic analyses revealed multiple independent duplications of the fatty acid desaturase gene Fads2 in stickleback lineages that subsequently colonized and radiated in freshwater habitats, but not in close relatives that failed to colonize. Transgenic manipulation of Fads2 in marine stickleback increased their ability to synthesize DHA and survive on DHA-deficient diets. Multiple freshwater ray-finned fishes also show a convergent increase in Fads2 copies, indicating its key role in freshwater colonization.

In-depth genomic analyses identified novel letermovir resistance-associated substitutions in the cytomegalovirus UL56 and UL89 gene products

2019 ◽  
Vol 169 ◽  
pp. 104549 ◽  
Author(s):  
Takashi E. Komatsu ◽  
Aimee C. Hodowanec ◽  
Anamaris M. Colberg-Poley ◽  
Andreas Pikis ◽  
Mary E. Singer ◽  
...  
Keyword(s):  
Gene Products ◽  
Genomic Analyses

scholarly journals Production of Polyhydroxyalkanoates and Extracellular Products Using Pseudomonas Corrugata and P. Mediterranea: A Review

2019 ◽  
Vol 6 (4) ◽  
pp. 105 ◽  
Author(s):  
Grazia Licciardello ◽  
Antonino F. Catara ◽  
Vittoria Catara
Keyword(s):  
Fermentation Process ◽  
Carbon Sources ◽  
Cost Effective ◽  
Production Costs ◽  
Bioactive Molecules ◽  
Pseudomonas Corrugata ◽  
Metabolic Potential ◽  
Medium Chain Length ◽  
Extracellular Products ◽  
Polylactide Acid

Some strains of Pseudomonas corrugata (Pco) and P. mediterranea (Pme) efficiently synthesize medium-chain-length polyhydroxyalkanoates elastomers (mcl-PHA) and extracellular products on related and unrelated carbon sources. Yield and composition are dependent on the strain, carbon source, fermentation process, and any additives. Selected Pco strains produce amorphous and sticky mcl-PHA, whereas strains of Pme produce, on high grade and partially refined biodiesel glycerol, a distinctive filmable PHA, very different from the conventional microbial mcl-PHA, suitable for making blends with polylactide acid. However, the yields still need to be improved and production costs lowered. An integrated process has been developed to recover intracellular mcl-PHA and extracellular bioactive molecules. Transcriptional regulation studies during PHA production contribute to understanding the metabolic potential of Pco and Pme strains. Data available suggest that pha biosynthesis genes and their regulations will be helpful to develop new, integrated strategies for cost-effective production.

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