The present study underlines a statistically optimized, low cost, effective approach for efficient co-valorization of two non-efficiently utilized, highly accumulated, raw agro-industrial wastes: corn cob and glycerol for co-production of natural biopigments: monascus orange and red pigments by the aid of Monascus purpureus strain ATCC 16436. A three step sequential, statistical modeling approach: one variable at a time (OVAT), Plackett-Burman design (PBD), and central composite design (CCD) was employed to optimize the production of monascus pigments using co-solid state fermentation of the two raw agro-industrial wastes. Corn cob among other carbon sources (e.g., rice grains, sugarcane bagasse, and potato peel) was the most appropriate substrate triggering co-production of orange and red monascus pigments; deduced from OVAT. Glycerol and inoculum size proved to impose significant consequences (P<0.05) on the production of monascus pigments as inferred from PBD. The optimal levels of inoculum size (12 x 10¹¹ spores/mL) and glycerol (2.17 M) did achieve a maximal color value of 133.77 and 108.02 color value units/mL of orange and red pigments, respectively at 30 ^oC after 10 days; concluded from CCD with an agitation speed of 150 rpm. Present data would underpin the large scale production of monascus pigments using the present approach for efficient exploitation of such biopigments in food, pharmaceutical and textile industries.

Background: In the context of searching for potent, safe, natural antimicrobial agents to combate the global antimicrobial resistance (AMR) phenomenon, the current study evaluates for the first time ever, the broad-spectrum antimicrobial activity of essential oil (EO) and extracts from the rare wild plant Centaurea pumilio L.. It has tremendous ethnomedicinal values; its dried root is used as a fattening agent, a treatment for bad breath and diabetes, and screened for schistosomicidal activity. Methods: C. pumilio EO was extracted by hydrodistillation using a Clevenger apparatus. Chemical constituents of aerial part were extracted using a sequential solvent/solvent procedure employing four solvents with increasing polarities in the following order: petroleum ether, chloroform, ethyl acetate, and n-butanol. The chemical constituents were identified by GC-MS. Fifty-two microbial strains were used; twenty-six multidrug resistant (MDR), sixteen clinical, and ten reference strains. The identification of the microbial strains was performed by MALDI-TOF-MS. The antimicrobial activity of the EO and the aerial part and the root extracts was assessed through disc diffusion assay. A minimum inhibitory concentration (MIC) of the EO and extracts was determined using the broth micro-dilution method. Results: The growth of reference and clinical strains was inhibited by EO, methanol, chloroform, and ethyl acetate aerial part extracts and chloroform root extract. The MDR strains growth, however, was inhibited only by EO and chloroform aerial part extract. GC-MS identified for the first time eighteen constituents from aerial part EO and chloroform extract each. EO showed antimicrobial activity against the reference, clinical, and MDR strains with MIC values of 31.25–125, 31.25–125, and 62.50–250 μg/mL, respectively. Methanol aerial part extract exhibited high antimicrobial activities with MIC values of 62.50–250 μg/mL against reference and clinical strains. Chloroform root extract displayed strong antimicrobial activity against reference and clinical strains recording MIC values of 62.50–250 μg/mL and 62.50–125 μg/mL, respectively. The chloroform aerial part extract demonstrated potent antimicrobial activity against the reference, clinical, and MDR strains with 31.25, 31.25, and 15.62 μg/mL MIC values, respectively. Conclusions: Present data unravel the C. pumilio pharmacological magnitude to discover eco-friendly potent antimicrobial agents to fight AMR phenomenon.

The current study underlines biotechnological valorization of the accumulated and the non-efficiently utilized agro-industrial orange peel waste to produce polygalacturonase (PGase), an industrially important enzyme with augmented demands in enzymes markets, from Bacillus licheniformis SHG10. Sequential statistical optimization of PGase production was performed through one variable at a time (OVAT) approach, Plackett-Burman (PB) and response surface methodology (RSM). The impact of introduction of six raw agro-industrial wastes (orange, lemon, banana, pomegranate, artichoke peel wastes and wheat bran) and other synthetic carbon sources separately into the fermentation broth on PGase productivity was studied through OVAT approach. Orange peel waste as sole raw carbon source in basal medium proved to be the best PGase inducer. It promoted PGase productivity with relative specific activity of 166% comparable with the effect imposed by synthetic citrus pectin as a reference inducer. Three key determinants (orange peel waste, pH of the production medium and incubation temperature) had RSM optimal levels of 1.76% (w/v), 8.0 and 37.8°C, respectively along with maximal PGase level (2.69 μg galacturonic acid. min-1. mg-1) within 48 hrs. Moreover, SHG10 PGase exhibited activity over a wide range of pH (3-11) and an optimal activity at 50°C. Data greatly encourage pilot scale PGase production from B. licheniformis SHG10.