. Bacteria in relation to plant diseases. Bacteriology; Plant diseases. BACTERIA IN RELATION TO PLANT Fig. them.* Some of them are very sen- sitive to the presence of acids, alka- lies, strong alcohol, or antiseptics, or their action is inhibited by the pres- ence of other enzymes or of products of enzymic fermentation in excess, or by the absence of some combining snbstance, such as lime or some weak acid. Some do not pass readily through the Chamberland filter or through filter papers. Some are destroyed at lower temperatures after precipitation. Some are not pro- duced excep
. Bacteria in relation to plant diseases. Bacteriology; Plant diseases. BACTERIA IN RELATION TO PLANT Fig. them.* Some of them are very sen- sitive to the presence of acids, alka- lies, strong alcohol, or antiseptics, or their action is inhibited by the pres- ence of other enzymes or of products of enzymic fermentation in excess, or by the absence of some combining snbstance, such as lime or some weak acid. Some do not pass readily through the Chamberland filter or through filter papers. Some are destroyed at lower temperatures after precipitation. Some are not pro- duced except in presence of the sub- stance which they can decompose, but this is not true of all. Usually an organism produces more than one ferment and some bacteria are known to produce five or six. Bac- tcriutn campestre produces at least three and probably four, viz, diasta- sic, cytohydrolytic, proteolytic, and rennet. It also inverts cane-sugar, but it is not j'et known whether this change is accomplished by means of an invertase. On enzymes derived from bacterial soft-rot organisms the reader should consult recent papers byJones(Centralb. f. Bakt, 2 Abt.,and Vermont Exp. Sta. Rep.). Levy has published an interesting paper on " Some physical properties of en- zymes" (The Jour. Infect. Diseases, Vol. II, 1905, pp. 1-48). For concentrating fluids in vacuo at low temperatures (50° to 60° C.) the thick-walled Kitasato flask shown *The same amount of dry heat does not affect them, and Locffler has recently advised exposure of thoroughly air-dried tissues and cultures to 150° C, dry heat, as an easy way of eliminating the bacteria prior to grinding and extraction of the uninjured enzymes and other soluble products. Non-sporiferous bacteria may be heated at 120° C. for 2 to 3 hours. Tissues and sporiferous bacteria should be heated at 150° C. ffir one-half hriur. (Deutsche Med. W'ochenschrift, Dec. 22, 1904.) fFir,. 59.—^Burettes used by the writer for titrating culture m
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