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Abstract

Marine Pseudoalteromonas piscicida was isolated from Hurghada, Red Sea, Egypt, it was identified using 16S rRNA. It showed amylolytic and agarolytic activities, it hydrolyzed some marine macro-algae, Ulvalactuca, Sargussumsp . and Pterocladias p. and produce marine monosaccharaides. The percentage of the carbohydrate content of these algae was estimated, it was 44%, 27% and 25%, respectively. The algal substrates were chemically pretreated using 1N H 2 SO 4 or 1 N NaOH. It was found that the acid pretreatment for U. lactucashowed more reducing sugars (17mg/g algae) compared to the alkaline pretreatment (9mg/g). Optimization of monosaccharaide production by P. piscicida was investigated using Plackett- Burmman design. The main effect data and the t -test results suggested the beef extract, substrate concentration and inoculum size are the most effective variables controlled the produced monosaccharaides by P. piscicida . The verification experiment showed an average monosaccharide production of 158mg/g algae on using the near optimum culture conditions. While, the main effect data and the t -test results of the produced amylase and agarase enzymes suggested the substrate concentration and incubation period are the most effective variables controlled the activity of these enzymes. The verification experiment showed an average enzyme activity of 35 and 41mm hydrolytic zoon, respectively, also on using the near optimum culture conditions. The interaction between these effective variables for both monosaccharaide production and the enzyme activity were carried out using the response surface plot analysis. The HPLC analysis of the produced monosaccharaides indicated the production of D-glucose and D-galactose in a ratio of 6:1 compared to the standard curves.

Biography

Manal M A El-Naggar has completed the PhD in microbiology at the age of 32 years from Alexandria University and postdoctoral studies from National Institute of Oceanography and Fisheries. He is the head of Microbiology Lab., Environ. Div., NIOF, Alex., Egypt. He has published more than 25 papers in reputed journals as Water Research Journal, Journal of Hazardous Materials, African Journal of Microbiology Research etc. He is a member of the National Committee of Microbiology 2013-2014, Egypt.