Marine microbial L-glutaminase: from pharmaceutical to food industry.

Deamination of L-glutamine to glutamic acid with the concomitant release of ammonia by the activity of L-glutaminase (L-glutamine amidohydrolase EC 3.5.1.2) is a unique reaction that also finds potential applications in different sectors ranging from therapeutics to food industry. Owing to its cost-effectiveness, rapidity, and compatibility with downstream processes, microbial production of L-glutaminase is preferred over the production by other sources. Marine microorganisms including bacteria, yeasts, and moulds have manifested remarkable capacity to produce L-glutaminase and, therefore, are considered as prospective candidates for large-scale production of this enzyme. The main focus of this article is to provide an overview of L-glutaminase producing marine microorganisms, to discuss strategies used for the lab- and large-scale production of these enzyme and to review the application of L-glutaminase from marine sources so that the future prospects can be understood. KEY POINTS: • L-glutaminase has potential applications in different sectors ranging from therapeutics to food industry • Marine microorganisms are considered as prospective candidates for large-scale production of L-glutaminase • Marine microbial L-glutaminase have great potential in therapeutics and in the food industry.

Determination of heavy metals in two barbs, Barbus grypus and Barbus xanthopterus in Karoon and Dez Rivers, Khoozestan, Iran.

Cadmium, lead, nickel and mercury were contamination in gill, liver and muscle of B. grypus and B. xanthopterus in Karoon and Dez Rivers. Significant variations in metal values were evaluated using student's t test at p < 0.05. In B. grypus high levels of cadmium, lead, nickel and mercury were measured in gill (1.49, 2.25, 1.02 and 0.89 mg kg(-1) dw) except for mercury (1.06 mg kg(-1) dw) in B. grypus in Dez River was high in liver. In B. xanthopterus high levels of cadmium, lead, nickel and mercury were measured in gill (2.17, 2.91 and 1.43 mg kg(-1) dw) except for mercury (1.42 mg kg(-1) dw) high levels were measured in liver.