Optimization of Low-Cost Culture Media for the Production of Biomass and Bacteriocin by a Urogenital Lactobacillus salivarius Strain

Abstract

The aim of this work was to formulate a culture medium of lower cost than conventional laboratory media, in order to simultaneously obtain high amounts of both biomass and bacteriocin of vaginal Lactobacillus salivarius CRL 1328. The growth assays under different culture conditions were performed by using a 2(8-2) central composite experimental design, with a central point and sixteen additional points. The factors taken into consideration were glucose, lactose, yeast extract, tryptone, ammonium citrate, sodium acetate, MgSO4 and MnSO4. The simultaneous presence of a carbon source (mainly glucose), a nitrogen source (mainly yeast extract) and salts (mainly MnSO4, MgSO4 and sodium acetate) allowed the highest cell biomass and bacteriocin levels to be reached in the experimental design. Through the application of the desirability function, several optimal medium compositions to achieve efficient production of biomass and bacteriocin were predicted. The optimized growth media allow a cost reduction of around 25 to 40% compared with conventional broths. The results obtained represent an advance in the search of the most suitable strategies for the production of bioactive compounds for pharmaceutical products to prevent or treat female urogenital infections.

Two-step production of anti-inflammatory soluble factor by Lactobacillus reuteri CRL 1098

“…These studies evaluate the application of economic and more competitive culture media for biomass production, because the growth medium is the most expensive factorat an industrial level [ 31 ]. Statistical models are often used for simplified media formulation, through the exclusion or reduction of components of the medium [ 15 , 32 , 33 ]. The initial approach involves the use of a statistical model, employing the conventional laboratory medium MRS. MRS broth remains the most widely used culture medium for LABgrowth [ 34 ].…”

“…The initial approach involves the use of a statistical model, employing the conventional laboratory medium MRS. MRS broth remains the most widely used culture medium for LABgrowth [ 34 ]. However, it is too expensive for industrial applications [ 15 ]. In this work, MRS medium is used for biomass production in the first step of the studied process.…”

“…Up to date, we did not find reports about culture media optimization for LAB peptides production under non-proliferating conditions. In contrast, several studies reported culture media optimization for bacteriocins production by LAB, antimicrobial peptides which synthesis is associated with bacteria growth [ 15 , 58 – 60 ]. In this work,sodiumcitrate buffer with glucose (2.37 USD/L) was selected for the anti-inflammatory compound production.…”

“…Therefore, a development of new culture media taking into account nutrient requirements and growth parameters could lead to a more economical probiotic production [ 14 ]. Statistical methodology is efficiently used to optimize several bioprocesses such as the development of a simplified, and hence more economical, culture medium, for biomass production [ 14 – 15 ]. In this situation, the fractional factorial designs have been successfully applied for studying the effects and interactions of distinct nutrients on Lactobacillus growth [ 15 – 17 ].…”

Screening of Medium Components and Process Parameters for Sugar Beet Molasses Vinasse Decolorization by Lactobacillus plantarum Using Plackett-Burman Experimental Design

“…Wheat stillage (X 1 ), yeast extract (X 2 ), glucose (X 3 ), peptone (X 8 ), (NH 4 ) 2 SO 4 (X 9 ), and agitation (X 10 ) were found to be significant for the decolorization process. Impacts of these factors on LAB cell growth and lactic acid production were reported in studies on selection of medium components for LAB [19][20][21].…”