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Menaquinone-7 (MK-7) is a type of vitamin K. MK-7 is produced via bacterial fermentation, and in order to reach the desired product purity, several downstream processing steps, including extraction, drying, ultrasonication, must be carried out. These processes, however, need to be carried out in such fashion to ensure the least amount of vitamin K lost and maximum recovery into the end-product. Therefore, in this study, drying, storage at 4 and −20 °C, and ultrasonication steps were evaluated under different conditions. Static liquid fermentations were conducted in McCartney bottles to explore the maximum MK-7 secretion potentials in different glycerol and glucose-based media compositions that were optimized in our previous studies. Maximum 32.5±0.4 mg l−1 and 14.6±0.4 mg l−1 concentrations were achieved in glycerol and glucose-based media, respectively. Concentrations of MK-7 produced under same fermentation conditions in 30 ml McCartney amber bottles with 3 ml of media in them and in 75 ml culture tubes with 20 ml media were compared. Also, ultrasonication, drying, and storage conditions were investigated to ensure the least amount of vitamin K is lost. Results showed that drying under forced air flow was the fastest, thus, demonstrated a better preservation of the vitamin, and should replace vacuum drying. Ultrasonication for 15 min seems to be safe and sufficient for phase transition for analysis. Also, storage at refrigerated temperatures seems to preserve MK-7 at least for one week. Furthermore, fermentations in McCartney bottles indicated how MK-7 concentrations are distributed in different zones of the static liquid broth. Culture tube results provided the conclusion as of how the metabolism of MK-7 changes in static fermentation when the scale-up process begins from McCartney bottle to culture tubes. Results in general showed a clearer road map to ensuring better quality and preservation of the valuable end-product, and illuminated more the path to further scaling up of the fermentation process for commercial production of MK-7.
– 1801 . C HANTAWANNAKUL , P. , O NCHAROAN , A. , K LANBUT , K. , C HUKEATIROTE , E. & L UMYONG , S. ( 2002 ): Characterization of protease of Bacillus subtilis strain 38
Clinical and Laboratory Standard Institute ( CLSI, 2018 ). Standard strains of E. coli ATCC 35218, S. aureus ATCC 25923, Bacillus cereus CCM 2010 and Bacillus subtilis WDCM 00003 were used. Bacterial cells were harvested in the logarithmic phase of
Extracts of five Euphorbia species were studied for their activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Candida albicans. E. amygdaloides and E. helioscopia proved to be the most effective against them. Some plant metabolits were also examinated against the microorganisms: podophyllin and rhamnetin caused the greatest, b-sitosterine the smallest inhibition among them. Bacillus subtilis was the least sensitive among the studied microorganism in this study.
Endophytic bacteria Bacillus subtilis (EPC 5) was isolated and tested in vitro along with Pseudomonas fluorescens (Pf1) and the fungus Trichoderma viride (Tv1) against Ganoderma lucidum (Leys) Karst, the causal agent of basal stem rot on coconut palm. The endophytic bacterial strains namely EPC 5 and EPC 8 showed higher vigor index (germination percentage, root and shoot length) and more inhibition against G. lucidum over un-inoculated control. These strains were confirmed as Bacillus subtilis by biochemical tests, cloning and sequencing of internal transcribed spacer (ITS) region. The Bacillus subtilis (EPC 5) along with Pseudomonas fluorescens (Pf1) and Trichoderma viride (Tv1) has been tried as bioconsortia against basal stem rot disease under greenhouse conditions. The soil application of bioconsortia enriched with farm yard manure (FYM) enhanced the coconut saplings growth under greenhouse conditions and showed higher induction of defense related enzymes like peroxidase, polyphenol oxidase, phenylalanine ammonia lyase and phenols when challenged with pathogen.
different microorganisms ( Staphylococcus haemolyticus ATCC 43252, Staphylococcus aureus ATCC 6538P, Bacillus subtilis ATCC 6633, Acinetobacter baumannii ATCC 19606, Escherichia coli NRRL B-3704, Pseudomonas aeruginosa ATCC 27853, Proteus
closely related to Bacillus subtilis with 99.2%–99.6% sequence similarity. Fig. 5. Neighbor-joining phylogenetic tree based on 16S rRNA gene sequences of the PGPR isolates from
A selective synthetic solid minimal medium (BS agar) was developed to detect antimicrobial drug-residues in foodstuffs using Bacillus subtilis indicator culture. This medium contains an ammonium salt as nitrogen source and either glucose or sodium pyruvate as carbon sources.Its selectivity is based on the fact that Bacillus subtilis is still able to grow if the minimal medium consists of simple inorganic substances as nitrogen sources, and glucose or pyruvate as carbon supply. Using these new synthetic media for microbiological assays assessing certain antimicrobials, the diameter of the inhibition zones were 1.4–4 times wider than on the Mueller-Hinton agar.The advantages of the BS agars are their standard compositions, the absence of inhibitors, the reproducible quality and the low costs.
on this approach, the research study was applied to investigate the effect of different extracts on various pathogenic bacteria including Enterobacter cloacae , Micrococcus leutus , Aeromonas hydrophila , Bacillus subtilis , Bacillus cereus
Abstract
Volatilization of polonium by microorganisms, Chromobacterium violaceum, Escherichia coli and Bacillus subtilis was examined for pure cultures in LB medium at 30 °C, showing relative Po emission intensity 100, 10 and 1, respectively. Chromobacterium violaceum pre-cultured in LB medium without Po and suspended in water with Po showed high Po volatilization in spite of poor nutriment condition. Antibiotics inhibit volatilization of Po and cultivation at low temperature greatly reduced volatilization. The results strongly support the biological effects on Po volatilization.
