Production and Purification of Anti-Bacterial Biometabolite from Wild-Type Lactobacillus, Isolated from Fermented Bamboo Shoot: Future Suggestions and a Proposed System for Secondary Metabolite Onsite Recovery During Continuous Fermentation

ABSTRACTMembers of theRoseobacterlineage of marine bacteria are prolific surface colonizers in marine coastal environments, and antimicrobial secondary metabolite production has been hypothesized to provide a competitive advantage to colonizing roseobacters. Here, we report that the roseobacterPhaeobactersp. strain Y4I produces the blue pigment indigoidine via a nonribosomal peptide synthase (NRPS)-based biosynthetic pathway encoded by a novel series of genetically linked genes:igiBCDFE. A Tn5-based random mutagenesis library of Y4I showed a perfect correlation between indigoidine production by thePhaeobacterstrain and inhibition ofVibrio fischerion agar plates, revealing a previously unrecognized bioactivity of this molecule. In addition, igiD null mutants (igiD encoding the indigoidine NRPS) were more resistant to hydrogen peroxide, less motile, and faster to colonize an artificial surface than the wild-type strain. Collectively, these data provide evidence for pleiotropic effects of indigoidine production in this strain. Gene expression assays support phenotypic observations and demonstrate thatigiDgene expression is upregulated during growth on surfaces. Furthermore, competitive cocultures ofV. fischeriand Y4I show that the production of indigoidine by Y4I significantly inhibits colonization ofV. fischerion surfaces. This study is the first to characterize a secondary metabolite produced by an NRPS in roseobacters.

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Transcriptional Profiling Identifies a Role for BrlA in the Response to Nitrogen Depletion and for StuA in the Regulation of Secondary Metabolite Clusters in Aspergillus fumigatus

Eukaryotic Cell ◽

10.1128/ec.00265-08 ◽

2008 ◽

Vol 8 (1) ◽

pp. 104-115 ◽

Cited By ~ 81

Author(s):

Kwame Twumasi-Boateng ◽

Yan Yu ◽

Dan Chen ◽

Fabrice N. Gravelat ◽

William C. Nierman ◽

...

Keyword(s):

Gene Expression ◽

Aspergillus Fumigatus ◽

Ribosomal Protein ◽

Secondary Metabolite ◽

Type Strain ◽

Wild Type Strain ◽

Protein Gene ◽

Ribosomal Protein Gene ◽

Wild Type ◽

Tor Pathway

ABSTRACT Conidiation (asexual sporulation) is a key developmental process in filamentous fungi. We examined the gene regulatory roles of the Aspergillus fumigatus developmental transcription factors StuAp and BrlAp during conidiation. Conidiation was completely abrogated in an A. fumigatus ΔbrlA mutant and was severely impaired in a ΔstuA mutant. We determined the full genome conidiation transcriptomes of wild-type and ΔbrlA and ΔstuA mutant A. fumigatus and found that BrlAp and StuAp governed overlapping but distinct transcriptional programs. Six secondary metabolite biosynthetic clusters were found to be regulated by StuAp, while only one cluster exhibited BrlAp-dependent expression. The ΔbrlA mutant, but not the ΔstuA mutant, had impaired downregulation of genes encoding ribosomal proteins under nitrogen-limiting, but not carbon-limiting, conditions. Interestingly, inhibition of the target of rapamycin (TOR) pathway also caused downregulation of ribosomal protein genes in both the wild-type strain and the ΔbrlA mutant. Downregulation of these genes by TOR inhibition was associated with conidiation in the wild-type strain but not in the ΔbrlA mutant. Therefore, BrlAp-mediated repression of ribosomal protein gene expression is not downstream of the TOR pathway. Furthermore, inhibition of ribosomal protein gene expression is not sufficient to induce conidiation in the absence of BrlAp.

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The Nutritional Facts of Bamboo Shoots and Their Usage as Important Traditional Foods of Northeast India

International Scholarly Research Notices ◽

10.1155/2014/679073 ◽

2014 ◽

Vol 2014 ◽

pp. 1-17 ◽

Cited By ~ 22

Author(s):

P. Nongdam ◽

Leimapokpam Tikendra

Keyword(s):

Effective Means ◽

Health Benefits ◽

Northeast India ◽

Habitat Destruction ◽

Market Potential ◽

Bamboo Shoot ◽

Traditional Foods ◽

Bamboo Shoots ◽

Fermented Bamboo Shoot

Bamboo shoots are considered as one of the useful health foods because of their rich contents of proteins, carbohydrates, vitamins, fibres, and minerals and very low fat. Though bamboo shoots provide lots of health benefits, their consumption is confined mostly to Southeast Asian and East Asian countries. The acceptability of bamboo shoots as popular vegetable crop is very less due to their high pungent smell and bitter acidic taste. The use of bamboo as food in India is mainly restricted to Northeastern part of the country where they form an indispensable part of several traditional speciality dishes. The different ethnic communities take fresh or fermented bamboo shoot as one of most preferred traditional food items. Some of the important bamboo based traditional foods are ushoi, soibum, rep, mesu, eup, ekhung, hirring, and so forth. Bamboo shoots should be properly processed before they are consumed as freshly harvested shoots have high content of toxic cyanogenic glycosides which may pose serious health problems. The prospect of bamboo shoot industry in Northeast India is bright due to its rich genetic resources of bamboos. However, habitat destruction and extensive use of bamboos for food, handicraft, and construction purposes have resulted in severe depletion of natural bamboo resources. This review stresses upon the high nutritive values and health benefits of bamboo shoots and their usage as important traditional foods in Northeast India. The bamboo market potential of the region and use of in vitro plant micropropagation methods as effective means of bamboo conservation are also emphasized in this paper.

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Bacterial species associated with traditional starter cultures used for fermented bamboo shoot production in Manipur state of India

International Journal of Food Microbiology ◽

10.1016/j.ijfoodmicro.2010.07.008 ◽

2010 ◽

Vol 143 (1-2) ◽

pp. 1-8 ◽

Cited By ~ 39

Author(s):

K. Jeyaram ◽

W. Romi ◽

Th. Anand Singh ◽

A. Ranjita Devi ◽

S. Soni Devi

Keyword(s):

Bacterial Species ◽

Starter Cultures ◽

Bamboo Shoot ◽

Shoot Production ◽

Fermented Bamboo Shoot

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The groEL2 gene, but not groEL1, is required for biosynthesis of the secondary metabolite myxovirescin in Myxococcus xanthus DK1622

Microbiology ◽

10.1099/mic.0.065862-0 ◽

2014 ◽

Vol 160 (3) ◽

pp. 488-495 ◽

Cited By ~ 14

Author(s):

Yan Wang ◽

Xi Li ◽

Wenyan Zhang ◽

Xiuwen Zhou ◽

Yue-zhong Li

Keyword(s):

Secondary Metabolite ◽

Mutant Strain ◽

Type Strain ◽

Wild Type Strain ◽

Myxococcus Xanthus ◽

Domain Swapping ◽

Wild Type ◽

Zone Of Inhibition ◽

Knockout Mutant ◽

E Coli

Myxococcus xanthus DK1622 possesses two copies of the groEL gene: groEL1, which participates in development, and groEL2, which is involved in the predatory ability of cells. In this study, we determined that the groEL2 gene is required for the biosynthesis of the secondary metabolite myxovirescin (TA), which plays essential roles in predation. The groEL2-knockout mutant strain was defective in producing a zone of inhibition and displayed decreased killing ability against Escherichia coli, while the groEL1-knockout mutant strain exhibited little difference from the wild-type strain DK1622. HPLC revealed that deletion of the groEL2 gene blocked the production of TA, which was present in the groEL1-knockout mutant. The addition of exogenous TA rescued the inhibition and killing abilities of the groEL2-knockout mutant against E. coli. Analysis of GroEL domain-swapping mutants indicated that the C-terminal equatorial domain of GroEL2 was essential for TA production, while the N-terminal equatorial or apical domains of GroEL2 were not sufficient to rescue TA production of the groEL2 knockout.

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