PRODUCTION OF LACTIC ACID BY Lactobacillus plantarum IN SEMI SOLID STATE FERMENTATION USING SOME RAW STARCHY MATERIALS.

Document Type : Original Article

Authors

1 Food Science Dept., Fac. Agric. Mansoura Univ. EI-Mansoura,Egypt

2 Microbiological Dept., Fac. Agric., Mansoura Univ., EI-Mansoura,Egypt

Abstract

Lactobacillus plantarum was selected to ferment raw starchy materials of 'rice
bran ,wheat bran and potatoes peel" to produce lactic acid and calcium lactate in
semi-solid state fermentation.
The noncooked starchy substrates were suspended in diluted solution of
sulfuric acid over night not only for the sterilization of the substrate,but also to help
the evolution of carbon dioxid upon addition of calcium carbonate( 0.5%) .,followed by
inoculation of the bacteria( 1 Ox1 09 CFU/1 Oml).
The selected organism produced lactic acid ranged from 0.49 to 0.75 gIL and
the yield of lactate ranged from 6 2 to 78 g IL of substrate.Maximum starch conversion
          to lactic acid was obtained after 120 h.at pH 6.5.                                                                  .
The addition of small amount of glucoamylase to the fermentation mixture .
resulted in a significant shortening of the fermentation process by Lactobacillus
pla
ntarum cultivated at 37 C,without any other additives.