Screening of Indigenous Bacterial Isolates from Dawadawa (African Locust Beans) in North Central Nigeria

Abstract

This study was undertaken to screen for Lactic Acid Bacteria (LAB) from indigenous fermented seeds; dawadawa. Isolation of LAB was carried out on MRS Agar. Biochemical, morphological and physiological examinations according to the Bergeys manual were used to identify the bacterial isolates. Six bacterial strains were obtained and given the designations DN, DO, DJ, DT, DG and DH respectively. The obtained colonies were all capable of fermenting lactose, sucrose, trehalose, glucose, maltose and lactulose as the sole carbon source in the broth. Morphological examination revealed that the isolates obtained were non-spore forming gram positive colonies ranging from creamy to white, clear, cocci and rod shaped, smooth textured and flat elevation with transparent opacity. Their growth profile study revealed that all isolates appeared to be mesophilc with progressive growth patterns observed between 24-96 hours at the same parameters for incubation. Isolates DO and DJ were observed to exhibit the fastest growth as determined by measuring optical density of the cells in broth using spectrophotometer at 550nm. Conclusions from the observed experiment indicate that isolated LABs from dawadawa could be applied in other probiotics as starter cultures and be improved for other commercial uses.