Pilot-scale production of Bacillus subtilis MSCL 897 spore biomass and antifungal secondary metabolites in a low-cost medium.

OBJECTIVES: Bacillus subtilis is a plant growth promoting bacterium (PGPB) that acts as a microbial fertilizer and biocontrol agent, providing benefits such as boosting crop productivity and improving nutrient content. It is able to produce secondary metabolites and endospores simultaneously, enhancing its ability to survive in unfavorable conditions and eliminate competing microorganisms. Optimizing cultivation methods to produce B. subtilis MSCL 897 spores on an industrial scale, requires a suitable medium, typically made from food industry by-products, and optimal temperature and pH levels to achieve high vegetative cell and spore densities with maximum productivity. RESULTS: This research demonstrates successful pilot-scale (100 L bioreactor) production of a biocontrol agent B. subtilis with good spore yields (1.5 × 109 spores mL-1) and a high degree of sporulation (>80%) using a low-cost cultivation medium. Culture samples showed excellent antifungal activity (1.6-2.3 cm) against several phytopathogenic fungi. An improved methodology for inoculum preparation was investigated to ensure an optimal seed culture state prior to inoculation, promoting process batch-to-batch repeatability. Increasing the molasses concentration in the medium and operating the process in fed-batch mode with additional molasses feed, did not improve the overall spore yield, hence, process operation in batch mode with 10 g molasses L-1 is preferred. Results also showed that the product quality was not significantly impacted for up to 12 months of storage at room temperature. CONCLUSION: An economically-feasible process for B. subtilis-based biocontrol agent production was successfully developed at the pilot scale.

Pichia pastoris growth-coupled heme biosynthesis analysis using metabolic modelling.

Soy leghemoglobin is one of the most important and key ingredients in plant-based meat substitutes that can imitate the colour and flavour of the meat. To improve the high-yield production of leghemoglobin protein and its main component-heme in the yeast Pichia pastoris, glycerol and methanol cultivation conditions were studied. Additionally, in-silico metabolic modelling analysis of growth-coupled enzyme quantity, suggests metabolic gene up/down-regulation strategies for heme production. First, cultivations and metabolic modelling analysis of P. pastoris were performed on glycerol and methanol in different growth media. Glycerol cultivation uptake and production rates can be increased by 50% according to metabolic modelling results, but methanol cultivation-is near the theoretical maximum. Growth-coupled metabolic optimisation results revealed the best feasible upregulation (33 reactions) (1.47% of total reactions) and 66 downregulation/deletion (2.98% of total) reaction suggestions. Finally, we describe reaction regulation suggestions with the highest potential to increase heme production yields.

Crypthecodinium cohnii Growth and Omega Fatty Acid Production in Mediums Supplemented with Extract from Recycled Biomass.

Crypthecodinium cohnii is a marine heterotrophic dinoflagellate that can accumulate high amounts of omega-3 polyunsaturated fatty acids (PUFAs), and thus has the potential to replace conventional PUFAs production with eco-friendlier technology. So far, C. cohnii cultivation has been mainly carried out with the use of yeast extract (YE) as a nitrogen source. In the present study, alternative carbon and nitrogen sources were studied: the extraction ethanol (EE), remaining after lipid extraction, as a carbon source, and dinoflagellate extract (DE) from recycled algae biomass C. cohnii as a source of carbon, nitrogen, and vitamins. In mediums with glucose and DE, the highest specific biomass growth rate reached a maximum of 1.012 h-1, while the biomass yield from substrate reached 0.601 g·g-1. EE as the carbon source, in comparison to pure ethanol, showed good results in terms of stimulating the biomass growth rate (an 18.5% increase in specific biomass growth rate was observed). DE supplement to the EE-based mediums promoted both the biomass growth (the specific growth rate reached 0.701 h-1) and yield from the substrate (0.234 g·g-1). The FTIR spectroscopy data showed that mediums supplemented with EE or DE promoted the accumulation of PUFAs/docosahexaenoic acid (DHA), when compared to mediums containing glucose and commercial YE.

The role of magnetic field in the biopharmaceutical production: Current perspectives.

Current scientific evidence on the influence of magnetic field on mammalian cell lines used for industrial production of biopharmaceuticals, on human cell lines and on potential cell lines for the biopharmaceutical production is presented in this review. A novel magnetic coupling induced agitation could be the best solution to eliminate sources of contamination in stirred tank bioreactors which is especially important for mammalian cell cultures. Nevertheless, the side effect of magnetically-coupled stirring mechanism is that cells are exposed to the generated magnetic field. The influence of magnetic field on biological systems has been investigated for several decades. The research continues nowadays as well, investigating the influence of various types of magnetic field in a variety of experimental setups. In the context of bioreactors, only the lower frequencies and intensities of the magnetic field are relevant.