ABSTRACT
The possibility of inducing genetic variability in the fungus Trichoderma reesei which produces cellulases upon treatment with different mutagenesis was investigated. The fungal strain NRRL-12368 was treated with UV-light, NTG, and combined treatment with both of them or combined treatment with UV-lightNaNO2. The results indicated that the treatment with UV-light induced 183colonies, 48 of them are morphological variants and 6 are auxotrophic mutants. When the NTG mutagen was applied, 48 colonies were isolated, 20 of them are morphological variants and only one is auxotrophic mutant. Using the combination between UV and NTG, 64 colonies were obtained, 24 of them are morphological variants and only one is auxotrophic. The combination between UV and NaNO2 gave 49 colonies, 11 of them are morphological variants and one is auxotrophic mutant. These mutants were evaluated for their productivity concerning the three cellulase enzymes FPase, CMCase and beta-glucosidase. Some mutants overyielded the parental strain in the cellulases production. The mutant S26 produced 180%, 102% and 31.6% FPase, CMCase and beta-glucosidase more than the original strain, respectively. No relationship can be found between the requirements of auxotrophic mutants and their cellulase activities, since some mutants lost their enzymes activity, some others produced one or more of these enzymes, whereas two mutants produced the three enzymes more than their parental strain
Subject(s)
Mutation , Cellulose , Mutagens , FermentationABSTRACT
Twenty wells of groundwater located in the vicinity of wastewater ponds were investigated to indicate the levels of water pollution during the four seasons of year [2000-2001]. Water samples were tested for the indicators of faecal pollution, heterotrophic plate count [HPC] at 25 and 37C, total coliform, faecal coliform, faecal streptococci, Clostridium perfringens, Pseudomonas aeruginosa, Campylobacter and Salmonella. Bacteriological analysis revealed that HPC at 25C exceeds that was counted at 37C in the examined water samples. A marked seasonal variation on the bacterial counts was observed where the high counts of most organisms were obtained in winter months. It recorded 130, 120 CFU/ml for TC and FC, respectively in the most contaminant well number [13], corresponding to 110, 90 CFU/ml in autumn season. Also, the secondary indicator microorganisms appeared relatively low counts while Salmonella sp. was not detected. High significant differences were observed between the tested bacterial counts, wells depth, distance from the wastewater ponds. Physicochemical analysis of water samples showed that some parameters such as turbidity, NH3+, NO2-, NO3-, K+, BOD5, COD and hardness exceeded the permissible level in many of tested wells. A relationship between the bacterial counts and physicochemical parameters was observed. Prepared questionnaire indicate that most the participants used to wells water without treatments suffering from various illnesses such as diarrhea, vomiting and other gastrointestinal problems specially in winter season
Subject(s)
Water Microbiology , Seasons , Water Pollution , Chemistry, Physical , HardnessABSTRACT
Trace elements content of scalp hair was done to 52 Egyptian children suffering from hypochromic microcytic anaemia, and living in industrial districts at low socioeconomic and nutritional status. The study revealed a significantly high content of lead and low content of zince and copper. The iron content was significantly increased in younger age group [1-6 years old], but within the normal range in the older age group [7-12 years old]. In the mean time serum iron was slightly decreased, while the serum iron binding capacity was within normal ranges. These results suggested a concomitant lead intoxication with iron deficiency anaemia in malnourished children who are at risk of lead exposure. Recommendations are suggested for further studies and for prevention