Protective role of the polysaccharide-containing capsular components of Azospirillum brasilense

The involvement of the carbohydrate components of the Azospirillum brasilen se Sp245 capsules in bacterial protection from the action of extreme factor s was investigated. The survival of encapsulated and nonencapsulated azospi rilla exposed to elevated (46-48 degreesC) and below-freezing (-20 and -70 degreesC) temperatures, extreme pH values (2 and 10), and to drying was stu died. High-molecular-weight carbohydrate-containing complexes (lipopolysacc haride-protein complex and polysaccharide-lipid complex) were isolated from the capsular material of azospirilla. It was shown that the addition of th ese complexes to the suspension of decapsulated cells before exposing them to extreme factors enhanced their survival rates by 15 to 51%.