Growth and metabolic properties of halophilic and alkaliphilic lactic acid bacterial strains of Marinilactibacillus psychrotolerans isolated from surface-ripened soft cheese

The behaviour of halophilic and alkaliphilic lactic acid bacteria (HALAB) during maturation of salted and surface-ripened soft cheese remains unclear; thus, physiological properties of HALAB was investigated. Marinilactibacillus psychrotolerans was the predominant HALAB (10(6)-10(10) cfu g(-1)) in the cheese rind of Maroilles cheese. To elucidate HALAB behaviour during maturation, sterilised cheese was matured using M. psychrotolerans B7-9-5 as an adjunct culture. During the ripening period, concentrations of lactate and acetate decreased and increased, respectively. Strain B7-9-5 produced only acetate from lactate under aerobic conditions, and the relevant genes are present in its genome. Unlike in the marine strain, strain B7-9-5 contains gene clusters for lactose and citrate catabolism and utilised these carbohydrates for growth. Thus, when carbon sources are limited during ripening, this strain survives by utilising, if any, lactate, lactose and citrate, and it may contribute to flavour formation during ripening of salted and surface-ripened soft cheeses. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The behavior of halophilic and alkalphilic lactic acid bacteria (HALAB) during the maturation process of salted and surface-ripened soft cheese was investigated. It was found that strain B7-9-5 of M. psychrotolerans produced acetate from lactate under aerobic conditions and could utilize lactose and citrate for growth, contributing to flavor formation during ripening.