Genome analysis of a thermophilic exopolysaccharide-producing bacterium - Geobacillus sp. WSUCF1

Abstract

Geobacillus sp. WSUCF1 is a Gram-positive, spore-forming, aerobic and thermophilic bacterium, isolated from a soil sample obtained from a compost facility. Strain WSUCF1 demonstrated EPS producing capability using different sugars as the carbon source. The whole-genome analysis of WSUCF1 was performed to disclose the essential genes correlated with nucleotide sugar precursor biosynthesis, assembly of monosaccharide units, export of the polysaccharide chain, and regulation of EPS production. Both the biosynthesis pathway and export mechanism of EPS were proposed based on functional annotation. Additionally, the genome description of strain WSUCF1 suggests sophisticated systems for its adaptation under thermophilic conditions. The presence of genes associated with CRISPR-Cas system, quorum quenching lactonase, polyketide synthesis and arsenic resistance makes this strain a potential candidate for various applications in biotechnology and biomedicine. The present study indicates that strain WSUCF1 has promise as a thermophilic EPS producer for a broad range of industrial applications. To the best of our knowledge, this is the first report on genome analysis of a thermophilic Geobacillus species focusing on its EPS biosynthesis and transportation, which will likely pave the way for both enhanced yield and tailor-made EPS production by thermophilic bacteria.

Genome Annotation of Poly(lactic acid) Degrading Pseudomonas aeruginosa, Sphingobacterium sp. and Geobacillus sp.

“…In addition, UDP-glucose 4-epimerase and mannose-1-phosphate guanylyltransferase, identified in Geobacillus sp. WSUCF1 [108], were also detected in strain EC-3.…”

Electricity from lignocellulosic substrates by thermophilic Geobacillus species

“…The 10-day growth profile indicated highest activity of laccase in supernatant on day six (460 IU/L), endoxylanase on day eight (270 IU/L), and endoglucanase on day ten (110 IU/L). A data mining exercise revealed the presence of genes encoding for hemicellulases (xylan 1,4-β-xylosidase, endo-1,4-β-xylanase, and xylan α-1,2-glucuronosidase), cellulases (endoglucanases, -glucosidases) and amylases in the genome of strain WSUCF1 28 , 30 – 32 . We observed that these enzymes displayed stable activity even after 10 days of the prolonged exposure at 60 O C, corroborating the thermostability of these enzymes, as reported in previous studies 33 , 34 (Fig.…”

“…The methods used for measuring the enzyme activities are given in the supplementary information. The enzyme assay studies revealed cellulase, hemicellulases and laccase in the WSUCF1 cultures ( www.nature.com/scientificreports/ cellulases (endoglucanases, -glucosidases) and amylases in the genome of strain WSUCF1 28,[30][31][32] . We observed that these enzymes displayed stable activity even after 10 days of the prolonged exposure at 60 O C, corroborating the thermostability of these enzymes, as reported in previous studies 33,34 (Fig.…”

“…In earlier studies, strain WSUCF1 was found to degrade lignocellulosic biomass under thermophilic and facultative anaerobic conditions 27 . It secretes large amount of extracellular polymeric substance 28 which may play a key role in the establishment and maintenance of biofilm structure 29 .…”

Adaptive Enrichment of a Thermophilic Bacterial Isolate for Enhanced Enzymatic Activity

“…Geobacillus sp. strain WSUCF1, a thermophilic microbe obtained from the compost pile in Washington State University, Pullman, Washington, USA (46.7319 • N, 117.1542 • W), is one such bacterium that produces highly thermostable lignocellulose deconstruction enzymes when grown on unprocessed lignocellulosic substrates, such as corn stover and prairie cordgrass [9,10]. WSUCF1 strain is highly efficient in depolymerizing unprocessed lignocellulose, needing no preprocessing/pretreatment of the biomasses; hence, utilization of WSUCF1 as a whole cell, or even its cells extract (for enzyme cocktails), is an attractive target for thermophilic bioprocessing of lignocellulosic biomasses.…”