The Abundance of Lactic Acid Bacteria in the Gastrointestinal Tract of Lake Victoria Nile Perch

Abstract

This study was carried out to determine the presence and abundance of lactic acid from gastrointestinal tracts of Latesniloticus fish with the specific objective of determining fish size effect on lactic acid bacteria (LAB) population. The study was conducted in Lake Victoria between April-June and July-September, 2014. Statistical analysis was performed by using Minitab 9.1.3 software version. Analysis of Variance (ANOVA) and east significant difference (LSD) was used for statistical comparisons. Differences were considered significant at α=0.05 level.  The average weight of small fish sampled during the wet season was 667.9g that gave an average colony forming units/g of 9.2x 10³; medium averaging 1485.1g had an average of 2.1x10⁴cfu and big averaging 3210.8g had 4.9 x 10⁴cfu. In the dry spells, the small fish averaging 614.6g had 6.7 x 10³, medium averaging 1392.9g had an average of 1.7x10⁴cfu and big averaging 2756.3g had 3.4 x 10⁴cfu. The mean of counts of LABs are significantly different for the three sizes tested, with the big size giving the highest followed by medium and small respectively. This could be due to ability to access more variety of foods. The means of counts of LABs are insignificantly different for the eight sites tested. The mean of counts of LABs are significantly different for the wet and dry seasons tested. In conclusion, this study showed availability of lactic acid bacteria in the gut of Lake Victoria Nile perch which can be used as a source of potential bio preservative.

Key words: Lactic Acid Bacteria (LAB), Gastrointestinal tracts, Nile perch, L. Victoria, ANOVA