. Annals of applied biology. Biology, Economic; Biochemistry. 256 Development of a Standardised Agar Medium It ?will be seen that with 2 per cent, agar the spreading ceases within five days, while with 1 per cent, agar it continues for a longer period, although the normal retardation of spreading is well shown. With 0-5 per cent, agar an interesting result appeared. As will be seen from the curve, the increase in colony area took place more slowly, but there was no falling off of the growth, the increase in area taking place quite steadily till the end of the experiment. This steady increase w
. Annals of applied biology. Biology, Economic; Biochemistry. 256 Development of a Standardised Agar Medium It ?will be seen that with 2 per cent, agar the spreading ceases within five days, while with 1 per cent, agar it continues for a longer period, although the normal retardation of spreading is well shown. With 0-5 per cent, agar an interesting result appeared. As will be seen from the curve, the increase in colony area took place more slowly, but there was no falling off of the growth, the increase in area taking place quite steadily till the end of the experiment. This steady increase was accompanied by an entire change in the form of growth. The colony was quite circular, nearly transparent and had an indistinct edge, which 50 r l-%Agar __^. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Days growth. Fig. 5. B. dendroides. Spreading growth with varying percentages of agar. was not produced into processes. The alteration in the mode and form of colony growth was due to the stiffness of the agar having been reduced to a point at which the motile organisms were able to penetrate the substance of the gel and progress slowly through it. When the growth was examined under a |-inch objective it was found that instead of forming a layer of surface growth, the rods were distributed throughout the agar, each rod lying separately and moving through the gel with a restricted, jerky motion. The colony grows as an ever-widening disc, since the forces which normally lead to the formation of branches do not operate. Also there is no faUing off of the rate of growth, since the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Association of Applied Biologists; Association of Economic Biologists. [Wellesbourne, Warwick, etc. ] Association of Applied Biologists [etc. ]
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbiochem, bookyear1922
