Title: The scale-up and culturability of live biotherapeutics for reproductive health in South Africa
Abstract:
Bacterial vaginosis is a highly prevalent inflammatory condition, characterised by the absence of protective. Lactobacillaceae commensal species and their replacement by vaginal pathogens such as Gardnerella vaginalis. It is known to increase HIV infection rates and thus presents a significant health risk to South African women. Traditional treatment is with antibiotics, but this does not support reestablishment of the natural protective vaginal species and thus recurrence rates of the condition are high. Treatment with probiotics that are endemic to South African women is proposed as an alternative to antibiotics. Screening of over 100 vaginal clinical isolates has been performed to identify the most promising Lactobacillaceae species. Desired characteristics included ability to adhere to vaginal epithelial cells, production of lactic acid [D and L] and H2O2, ability to lower pH, and inhibition of common vaginal pathogen growth. This work concerns characterising the production potential of the top five novel South African probiotic vaginal Lactobacillaceae isolates, for the treatment of bacterial vaginosis. The project investigates the cultivation and scale-up requirements of the isolates. Five Lactobacillaceae were cultured in MRS Broth at 37°C and 140 RPM, scaling up from 100 mL serum bottles to 5 000 mL bioreactors. pH control was also investigated in the bioreactors. Culture pH and cell density were also measured. Substrate and product concentrations were quantified via HPLC. The strains’ performances were quantified with respect to their maximum specific growth rate, biomass and bioproduct yields, ability to lower pH, and their substrate to biomass, substrate to bioproduct, and bioproduct to biomass yield coefficients, and these were all compared to currently established over-the-counter probiotic strains. The work seeks to establish an understanding and proof of concept to cultivate, at scale, the top performing live cultures to produce probiotics to treat bacterial vaginosis, adjunctively with antibiotics, in South Africa.
Audience Take Away Notes:
- The research highlights issues involved with scaling up processes, especially where biomass is the key product
- Brings an understanding of physicochemical factors that limit and inhibit the growth of probiotic products, particularly Lactobacillaceae strains
- The audience will learn which bioprocessing parameters are key to consider upon designing a biotherapeutic whose primary product is biomass
- The work demonstrates how the novel South African probiotic strains compare to currently established over-the-counter probiotic strains
- The work interrogates the feasibility of currently existing growth media that are used in industry, from an economic and fit-for-application standpoint
