The Intestinal Microflora of the Clothes Moth Larva Tineola bisselliella in relation to Wool Digestion

Abstract

SUMMARY:The intestines of clothes moth larvae, Tineola bisselliella, examined usually contained very few micro-organisms; this may be related to the high pH values of the intestinal contents. It was concluded that bacteria play no part in the digestion of wool by these larvae.It was shown by Linderstram-Lang & Duspiva (1936) and by Waterhouse (1952) that the mid-gut of the clothes moth larva, Tineola bisselliella, has a reduction potential of c. -250 mV. at pH values near 10. These reducing conditions, thought to assist the digestion of keratin, might result from the metabolic processes of micro-organisms within the intestine. We therefore examined the intestinal microflora of the moth larvae. METHODSLarvae were obtained from laboratory cultures growing on unsterilized lactic casein powder (90-mesh) containing 10% dried yeast powder, and from naturally occurring colonies on greasy wool. Laboratory cultures on wool were obtained by transference of larvae or eggs from casein medium to greasy wool and incubation a t the optimal temperature of 28". Larval intestines were withdrawn aseptically after circular incision of the skin near the head and amputation of the tail tip.Emulsions of four to six intestines in 0.05 ml. peptone water were equally distributed on six plates of nutrient agar containing 1 yo (w/v) glucose and 0.5 yo (w/v) yeast extract adjusted to pH values 7.5, 8.5 and 9.5. Plates were incubated aerobically and anaerobically a t 28'.

Larvae of the Clothing Moth Tineola bisselliella Maintain Gut Bacteria that Secrete Enzyme Cocktails to Facilitate the Digestion of Keratin

“…An alternative explanation for the adaptation of the clothing moth to keratin-based diets is that keratinase activity is conferred by specific bacterial symbionts in the gut. Although previous studies found no abundant microorganisms in T. bisselliella larvae [21,22], we were able to reproducibly isolate bacteria from the midgut of larvae fed on a feather diet. Most of the isolates were identified as Clostridiales, Lactobacillales, and the genus Bacillus, similar to the bacteria associated with the brown house moth Hofmannophila pseudospretella, another keratin-feeding lepidopteran [23].…”

Bacterial Symbionts in Lepidoptera: Their Diversity, Transmission, and Impact on the Host

“…Since keratinases are only known from bacteria and fungi ( Hughes and Vogler, 2006 ), it is possible that a microbial partner is involved in this digestion. Despite this, the mechanism by which T. bisselliella uses keratin is yet to be clarified, firstly because Crewther and Mcquade (1955) did not find any culturable bacterial colonies in the gut that could play this role, and secondly because the complete microbiome of this species has not been characterized. In addition, genes that resemble bacterial sequences encoding keratinolytic enzymes were not found in the genome of this moth in a later study ( Hughes and Vogler, 2006 ).…”

Characterization of lactic acid bacteria in the larval midgut of the keratinophagous lepidopteran, Hofmannophila pseudospretella

“…Many insects are known to have micro‐organisms in the gut which can play a role in nutrition (Slansky and Rodriguez 1987). However, studies on the keratinophagous larva of Tineola bisselliella (Lepidoptera, Tineidae) found no evidence for the presence of micro‐organisms in the midgut (Crewther and McQuade 1955; Kasper 1978) other than a single specimen infected with a microsporidium.…”