Effect of Some Lactic Acid Bacteria on Some Parameters of the Silkworm , Bombyx Mori L.

Abstract

Effect of lactic acid bacteria (Lactobacillus rhamnoses, Lactobacillus paracasei and Lactobacillus acidophilus) as food additives on some parameters of Bombyx mori L. was carried out . Experimental product of Lactic acid bacteria was dissolved in distilled water to prepare one concentration (5mg/ml.) from bacteria in addition to yoghurt and milk. The obtained results showed that, Lactobacillus acidophilus occupied the first category for improving the most studied parameters of B. mori when comparing to control. Where the 5th instar larval weights were 2.159g compared to 2.002 g in control , effective rate of rearing recorded 82.00% compared to 78.00% in control and total haemolymph protein recorded 64.00mg/ml. compared to 60.99mg/ml. in control. Cocoon indices registered 1.101 g, 0.209 g and 18.98% for cocoon weight, cocoon shell weight and cocoon shell ratio comparing to 1.005 g, 0.177 g and 17.61% for the control respectively. INTRODUCTIONThe silkworm is the larva or caterpillar of the domesticated silk moth, Bombyx mori belonging to the Family Bombycidae. It is an important economic insect since it is the producer of silk. Sericulture or silk farming is the rearing of silkworms for the production of raw silk although there are several commercial species of silkworms, Bombyx mori is the most widely used and intensively studied.Probiotics are organisms and substances which contribute to intestinal microbial balance (Parker, 1974). Lactic acid bacteria (LAB) are a group of Gram-positive, non-sporulating bacteria that includes species of Lactobacillus, Leuconostoc, Pediococcus and Streptococcus. Dietary LAB refers to those species and strains that are used in food and feed fermentation processes. The term LAB does not reflect a phyletic class, but rather a group of organisms that are defined by their ability to produce a common end product lactic acid from the fermentation of sugars. LAB have limited biosynthetic abilities, and require pre-formed amino acids, B vitamins, purines, pyrimidines and, usually a sugar as a carbon and energy source. These nutritional requirements restrict their habitats to those in which the required compounds are abundant (Oh et al., 2000). The gut probiotics are involved in the digestive utilization of feeds and detoxification of metabolite, stimulation of non-specific immune system.