Studies on the keratinolytic enzymes of thermophilic actinomycetes.1-Production of thermostable keratinase enzyme and identification of keratinolytic thermophilic actinomycetes

One hundred and ninety thermophilic actinomycetes were isolated from different sources. Screening was carried out according to growth temperatures. Obligate thermophilic actinomycetes were picked up and examined according to their keratinolytic activity. Results indicated that five isolates have keratinase activity. The two most active keratinolytic actinomycete isolates C52 and G114 were selected and subjected to complete identification. The cultural, morphological and physiological characteristics of both isolates indicated that they belong to Theinoactinomyces vulgaris and Microbispora thermodiastatica. The effect of nutritional and environmental conditions on the growth and keratinase activity of Th. vulgaris C52 were studied. Data revealed that Th. vulgaris C52 grew better with good yield of keratinase activity by growing it on the modified Kosmatchev medium [50 ml medium/500 ml clinical bottle], in which the nitrogen and the carbon sources of the Kosmatchev medium were replaced with 1.6% [W/V] sterile chicken feather pieces and 1% [W/V] starch, using tap water with an initial pH of 7.5, inoculated with 2% [v/v] of homogenized spore suspension [containing approximately 7.5 x 10 4 spores ml-1] of one day old culture and incubated at 50§C for 4 days under static condition

Farmer's lung disease in north-western India--a preliminary report.

A study of farmer's lung (FL) disease was carried out in 197 subjects engaged in farming and having respiratory complaints of varying duration. It revealed that 13.2% of the subjects had precipitating antibodies against thermophilic actinomycetes, with Faenia rectivirgula (Micropolyspora faeni) alone accounting for 85% of the positive reactions. Precipitating antibodies against Thermoactinomyces vulgaris and T. thalpophilus were observed only in 1.5% and 0.5% of the subjects, respectively. Two subjects concomitantly demonstrated F. rectivirgula and T. vulgaris-specific serum precipitins. Sixty (30%) of the subjects related their respiratory symptoms to exposure to wheat straw/thresher's dust or other vegetable substrata in the working environment. Based upon a suggestive clinical history, roentgenography, pulmonary function studies and demonstration of serum precipitins against F. rectivirgula, FL was diagnosed in 4 subjects whose salient features are presented and discussed. To the best of our knowledge, this is the first authentic report on FL from India. A comprehensive epidemiological survey is indicated to determine the prevalence of FL in different geo-climatic regions of the country.