No abstract

Propionic acid (PA) is a valuable organic acid for the food and feed industry, but no bioproduction at industrial scale exists so far. As product inhibition is a major burden for bioprocesses producing organic acids, in situ product removal (ISPR) is desirable. Here, we demonstrate a new strategy to produce PA with a co-culture coupled with ISPR using electrodialysis. Specifically, Bacillus coagulans first produces lactic acid (LA) from sugar(s) and LA is converted to PA using Veillonella criceti. Applying ISPR to the mentioned co-culture, the specific PA yield was increased from 0.35 to 0.39 g g −1 compared to no ISPR usage. Furthermore, the productivity was increased from 0.63 to 0.7 g L −1 h −1 by applying ISPR. Additionally, it was shown that co-consumption of xylose and glucose led to a higher PA productivity of 0.73 g L −1 h −1 , although PA yield was only increased slightly up to 0.36 g g −1 .

In the present study, a phyto-mediated synthesis of gold nanoparticles (AuNPs) using an isoflavone, Dalspinosin (5,7dihydroxy-6,3′,4′-trimethoxy isoflavone) isolated from the alcoholic extract of roots of Dalbergia coromandeliana is reported. It is observed that Dalspinosin itself acts both as a reducing and a capping agent in the synthesis of the nanoparticles (NPs). An ultraviolet-visible (UV-Vis) spectral study showed a surface plasmon resonance band at 526 nm confirming the formation of AuNPs. The NPs formed were characterised by UV-Vis spectroscopy, Fourier transform-infrared spectroscopy, X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM) with energy-dispersive x-ray spectroscopy (EDX) and dynamic light scattering. HR-TEM analysis showed the synthesised AuNPs were spherical in shape with a size of 7.5 nm. The AuNPs were found to be stable for seven months when tested by in vitro methods showed good antioxidant and antiinflammatory activities. They also showed moderate anti-microbial activities when tested against Gram positive (Staphylococcus aureus and Streptococcus sp), Gram negative bacterial strains (Klebsiella pneumonia and Klebsiella terrigena) and fungal strain (Candida glabrata). The biosynthesised AuNPs showed significant catalytic activity in the reduction of methylene blue with NaBH 4 to leucomethylene blue.

A study on curcumin seed invigoration for extending the storability of blackgram seeds under accelerated ageing was undertaken during 2021. Genetically pure seeds of blackgram (VBN 8) were treated with curcumin at different concentrations viz., 20,40,60,80,100 and 120 mg per kg. The treated seeds were subjected to accelerated ageing for 10 days. Every day of accelerated ageing, required quantity (50-100g) of seed samples were drawn and tested for physiological and biochemical seed quality attributes. The results revealed that the seeds invigorated with curcumin at 80 mg per kg of seeds significantly registered higher germination (66%), root (11.3cm) and shoot length (16.3cm) seedling vigour index I (1813) and II (12), alpha amylase (0.97µmol starch hydrolysed min-1 mg-1 protein) and dehydrogenase (1.642 OD value) enzymes activity. Overall results of this study conclude that blackgram seeds invigorated with curcumin at 80 mg per kg excelled the other treatments, irrespective of the accelerated ageing period.

Turmeric can be used as aromatic, stimulant, preservative, flavouring and colouring agent in diet and it also has various medicinal properties. Turmeric mainly consists of curcuminoids, volatile oils and water soluble peptide. Curcumin is insoluble in water, photosensitive and unstable in alkaline pH and so curcumin has less bioavailability in the body due to inadequate absorption from the gastrointestinal track, higher metabolic rate and faster excretion. The study aims to develop encapsulated curcumin nano formulation with higher bioavailability and product stability. The prepared curcumin nanoformulation was basically a nanoemulsion which consists of aqueous and organic phase. The mean droplet size of nanoemulsion was found to be 72.6nm, the polydispersity index was 0.478 and zeta potential was -50.2 mV after 1 hour ultrasonication with the surfactant concentration of 2.5 ml. The FTIR finger print confirms the presence of most of the absorption peaks pertaining to curcumin and beta cyclodextrin in the nanoformulation. The XRD pattern of curcumin nanoformulation showed that the crystallinity of the curcumin had decreased when curcumin was encapsulated within the carrier molecule thereby enhancing the aqueous solubility. Under thermo gravimetric analysis of nano formulation, the absence of peak at 185˚C indicated that the curcumin was completely encapsulated into the carrier molecule.