A novel medium for the production of cephamycin C by Nocardia lactamdurans using solid-state fermentation

Methionine inducing carbohydrate esterase secretion of Trichoderma harzianum enhances the accessibility of substrate glycosidic bonds

BACKGROUND

The conversion of plant biomass into biochemicals is a promising way to alleviate energy shortage, which depends on efficient microbial saccharification and cellular metabolism. Trichoderma spp. have plentiful CAZymes systems that can utilize all-components of lignocellulose. Acetylation of polysaccharides causes nanostructure densification and hydrophobicity enhancement, which is an obstacle for glycoside hydrolases to hydrolyze glycosidic bonds. The improvement of deacetylation ability can effectively release the potential for polysaccharide degradation.

RESULTS

Ammonium sulfate addition facilitated the deacetylation of xylan by inducing the up-regulation of multiple carbohydrate esterases (CE3/CE4/CE15/CE16) of Trichoderma harzianum. Mainly, the pathway of ammonium-sulfate's cellular assimilates inducing up-regulation of the deacetylase gene (Thce3) was revealed. The intracellular metabolite changes were revealed through metabonomic analysis. Whole genome bisulfite sequencing identified a novel differentially methylated region (DMR) that existed in the ThgsfR2 promoter, and the DMR was closely related to lignocellulolytic response. ThGsfR2 was identified as a negative regulatory factor of Thce3, and methylation in ThgsfR2 promoter released the expression of Thce3. The up-regulation of CEs facilitated the substrate deacetylation.

CONCLUSION

Ammonium sulfate increased the polysaccharide deacetylation capacity by inducing the up-regulation of multiple carbohydrate esterases of T. harzianum, which removed the spatial barrier of the glycosidic bond and improved hydrophilicity, and ultimately increased the accessibility of glycosidic bond to glycoside hydrolases.

Characterization of pigment produced by high carotenoid yielding bacteria Paracoccus marcusii RSPO1 and evaluation of its anti-diabetic, anti-microbial and antioxidant properties

High pigment producing bacteria was isolated and identified as Paracoccus marcusii RSPO1 using biochemical and 16s rRNA identification. Bacterial pigment production was optimised using parameters like inoculum size, nitrogen source, pH, temperature, and agitation speed. Carotenoids production was 7,240 ± 41 µg L-1 after optimization. The silica column purified pigment was characterized using UV-visible spectroscopy, TLC, FTIR, LC-ESI-MS and NMR, which revealed its composition as astaxanthin, zeaxanthin, ζ-carotene and β-zeacarotene. The inhibition assays against α-amylase and α-glucosidase showed IC50 values as 226 µg ml-1 and 0.7548 µg ml-1 respectively. The MIC of 1000 µg ml-1 of carotenoid was found to be effective against Escherichia coli and Enterobacter aerogenes when tested for antibacterial activity. Moreover, antioxidant activity of carotenoid sample was also determined where antioxidant potential of extracted carotenoid for DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) inhibition were 65 ± 0.06% and 42 ± 07% respectively at 20 µg ml-1 concentration.

Interdependent nitric oxide and hydrogen peroxide independently regulate the coix seed oil-induced triterpene acid accumulation in Ganoderma lingzhi

Recent progress has been made in adding exogenous vegetable oils in culture media to promote bioactive metabolite production in several medicinal mushrooms, but the mechanism is still unclear. In this study, we found that the vegetable oil coix seed oil (CSO) could induce the biosynthesis of triterpene acids (TAs) and also significantly increase cytoplasmic nitric oxide (NO) and hydrogen peroxide (H₂O₂) concentrations in the mycelium of Ganoderma lingzhi. The change in TA biosynthesis caused by CSO could be reversed by adding NO scavenger or H₂O₂ scavenger, and adding NO scavenger or H₂O₂ scavenger resulted in the reduction of the cytoplasmic H₂O₂ or NO concentration under CSO treatment, respectively. Moreover, adding NO scavenger or H₂O₂ scavenger reversed TA biosynthesis, which could be rescued by H₂O₂ or NO donor, respectively. Taken together, our study indicated that both NO and H₂O₂ were involved in the regulation of TA biosynthesis, and CSO-activated NO and H₂O₂ were interdependent but independently regulated the TA biosynthesis under CSO treatment in G. lingzhi.

Enhancing cordycepin production in liquid static cultivation of Cordyceps militaris by adding vegetable oils as the secondary carbon source

This study evaluated different vegetable oils as the second carbon source in liquid static culture of Cordyceps militaris in terms of mycelial growth and cordycepin production. The maximum mycelial concentration and cordycepin production were observed under cottonseed oil and peanut oil induction, respectively. In the condition of adding 20 g/L of peanut oil at Day 0, the final concentration of cordycepin reached to the highest, about 5.29 g/L, which was about 3.17 times higher than that of the control. The qRT-PCR and enzyme activity analysis confirmed that addition of peanut oil up-regulated the expression of the genes encoding glucose-6-phosphate dehydrogenase and isocitrate lyase, as well as the genes in the cordycepin biosynthesis pathway, cns1 and cns2, during the cultivation in C. militaris.

Enhancing effect of lysine combined with other compounds on cephamycin C production in Streptomyces clavuligerus

BACKGROUND

Lysine plays an important role in Streptomyces clavuligerus metabolism; it takes part in its catabolism, via cadaverine, and in its secondary metabolism, in which lysine is converted via 1-piperideine-6-carboxylate to alpha-aminoadipic acid, a beta-lactam antibiotic precursor. The role of lysine as an enhancer of cephamycin C production, when added to production medium at concentrations above 50 mmol l(-1), has already been reported in the literature, with some studies attributing a positive influence to multifunctional diamines, among other compounds. However, there is a lack of research on the combined effect of these compounds on antibiotic production.

RESULTS

Results from experimental design-based tests were used to conduct response surface-based optimization studies in order to investigate the synergistic effect of combining lysine with cadaverine, putrescine, 1,3-diaminopropane, or alpha-aminoadipic acid on cephamycin C volumetric production. Lysine combined with cadaverine influenced production positively, but only at low lysine concentrations. On the whole, higher putrescine concentrations (0.4 g l(-1)) affected negatively cephamycin C volumetric production. In comparison to culture media containing only lysine as additive, combinations of this amino acid with alpha-aminoadipic acid or 1,3-diaminopropane increased cephamycin C production by more than 100%.

CONCLUSION

This study demonstrated that different combinations of lysine with diamines or lysine with alpha-aminoadipic acid engender significant differences with respect to antibiotic volumetric production, with emphasis on the benefits observed for lysine combined with alpha-aminoadipic acid or 1,3-diaminopropane. This increase is explained by mathematical models and demonstrated by means of bioreactor cultivations. Moreover, it is consistent with the positive influence of these compounds on lysine conversion to alpha-aminoadipic acid, a limiting step in cephamycin C production.

Bioactive polyketides isolated from agar-supported fermentation of Phomopsis sp. CMU-LMA, taking advantage of the scale-up device, Platotex

Phomopsis sp. CMU-LMA was cultivated on agar-supported fermentation (Ag-SF) using the scale-up prototype Platotex. In total nine compounds were isolated from the ethyl acetate extract of the culture. Among them, compounds LMA-P1, Sch-642305, DHTO and LMA-P2 had already been reported in our previous work on liquid state fermentation. The trihydroxybenzene lactone cytosporone D and dothiorelone A has been recently isolated from Phomopsis and Magnaporthe species. In addition, three compounds were isolated consisting in the reduced methoxy derivative of Sch-642305 (1), a hydroxylated derivative of LMA-P2 (2) and a linear ethyl ester polyketide (3) similar to the previously reported LMA-P3. Antimicrobial activity and inhibition of Escherichia coli DnaG primase were investigated. Cytosporone D inhibited the E. coli DnaG primase, a Gram-negative antimicrobial target, with an IC50 of 0.25 mM.

Bioactive phenolic compounds: production and extraction by solid-state fermentation. A review

Interest in the development of bioprocesses for the production or extraction of bioactive compounds from natural sources has increased in recent years due to the potential applications of these compounds in food, chemical, and pharmaceutical industries. In this context, solid-state fermentation (SSF) has received great attention because this bioprocess has potential to successfully convert inexpensive agro-industrial residues, as well as plants, in a great variety of valuable compounds, including bioactive phenolic compounds. The aim of this review, after presenting general aspects about bioactive compounds and SSF systems, is to focus on the production and extraction of bioactive phenolic compounds from natural sources by SSF. The characteristics of SSF systems and variables that affect the product formation by this process, as well as the variety of substrates and microorganisms that can be used in SSF for the production of bioactive phenolic compounds are reviewed and discussed.