Assesment of chemical method for measuring fungal biomass on rice and corn

• Main Authors: Yang, Wan Rong, 楊宛蓉
• Other Authors: You, Ruo
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/29093968815814506589

碩士 === 國立臺灣大學 === 食品科技研究所 === 84 === The measurement of glucosamine content in fungal mycelium by chemical mehtod was usually used for evaluating fungal biomass on cereal grains.In this study,chitin of fungal mycelium was first hydrolyzed by hydrochloric acid,and the resulting glucosamine was then quantified by colorimetric method. The results showed tgeat hydrolysis yield under acid condition was 0.945,and recovery yield depended on the difference of strains varied among 0.70-0.90.When growth of fungal mycelium on cereal grains was quantified by this method,the presence of interference glucosamine in the cereal grains interfered with the accuracy of this measurement.From the ratio of glucosamine to the dry weight in pure mycelium,glucosamine-to-biomass conversion factor was determined and was used to measure fungal mycelium on cereal grains. Results showed that the proportion of glucosamine to the weight of the mycelium varied with incubation time, incubation temperature, culture medium and environment in the fungus grown.When conversion factors were used for the measurement of mixed mycelium, the accuracy of speices-specific conversion factors was among 0.73-1.25, and the accuracy of general conversion factor was 0.70-1.30.Moisture migration was occurred on rice and corn when they were inoculated with 1 ml 1000000 spores/ ml spore suspension and incubated at 30C, 70RH for various time. After two days of incubation, total glucosmaine content of rice and corn substrates were increased than substrates without inoculation, indicating that under the growth condition, cereal grains might be unsafe due to the growth of fungi.