plant surface microbiology.pdf

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Giang Huong Pham et al.
The morphology of the colonies differed according to the sugar supply. In
fructose and sucrose, the colonies were roundish and compact, in glucose they
were large and irregular with short and long protrusions (Fig. 9).
7 Biomass on Individual Amino Acids
The addition of glycine, methionine, serine, alanine promoted fungal growth
to different extents (Table 7). Not much difference in mycelial growth was
observed in media containing glutamine, asparagine and histidine, although a
substantial difference in the end pH of these amino acid-fortified culture
broths was recorded (Table 7).
8 Growth on Complex Media
P. indica grown in minimal broth was transferred onto one set of fresh minimal
media containing agar. In the minimal broth, the complex mixtures such as
soil-extract, malt-extract, peptone, beef-extract, yeast-extract and caseinhydrolysate
were added individually to an amount of 1 % (w/v). Before autoclaving,
the pH of the media was adjusted to 6.5. Compared to all other media
used,excellent growth of mycelium was recorded in the incubation broth fortified
with casamino hydrolysate-HCl. Growth in beef, yeast, malt extracts and
peptone was moderate. Soil extracts did not support fungal growth (Table 8).
Table 7. End pH and fungal biomass grown on minimal broth medium supplemented
with amino acids (each 0.5 % w/v)
Amino acids End pH Biomass (mg/10 ml)
Control (no addition) 5.14 3.8
Alanine 6.94 6.2
Phenyl alanine 4.31 5.8
Methionine 4.71 7.0
Serine 5.82 6.9
Asparagine 5.86 4.2
Glutamine 4.76 4.3
Cysteine 1.90 3.8
Glycine 5.01 7.8
Aspartic acid 2.91 3.8
Arginine 8.93 3.8
Histidine 7.05 4.0
pH was re-adjusted after the addition of microsyringe-filtered amino acids to 6.5. Incubation
was done under constant shaking condition (GFL, 3026, Germany) for 7 days at
25 °C. Fungal biomass was removed and end pH was measured