Crustacean hyperglycemic hormone (CHH) has many functions to regulate carbohydrate metabolism, ecdysis and reproduction including ion transport in crustaceans. The cDNA encoding CHH peptides containing 369 bp open reading frame encoding 122 amino acids was cloned from eyestalk of white shrimp (Litopenaeus vannamei) and was produced by a bacterial expression system. The biological activity of re...

Relatively little is known about the number, diversity, and function of chitinases produced by bacteria, even though chitin is one of the most abundant polymers in nature. Because of the importance of chitin, especially in marine environments, we examined chitin-degrading proteins in the marine bacterium Vibrio harveyi. This bacterium had a higher growth rate and more chitinase activity when gr...

Aquaculture is the fastest growing food sector globally and is established itself as high protein resource to fulfill the food demand since the natural resources exhibits over exploitation. But, presently, the biggest problem faced by the aquaculture industry worldwide is diseases caused due to various biological and non-biological agents. Among the groups of microorganisms that cause serious l...

Our previous studies showed that the Aggregatibacter actinomycetemcomitans RbsB protein interacts with cognate and heterologous autoinducer 2 (AI-2) signals and suggested that the rbsDABCK operon encodes a transporter that may internalize AI-2 (D. James et al., Infect. Immun. 74:4021-4029, 2006.). However, A. actinomycetemcomitans also possesses genes related to the lsr operon of Salmonella ent...

When isogenic strains of Escherichia coli, RR1 (rec+) and HB101 (recA), were transformed with mapped recombinant plasmids known to contain Vibrio harveyi luciferase genes and large regions of DNA flanking on both sides, a small percentage (0.005%) of the colonies expressed high levels of luminescence (up to 10(12) quanta s-1 ml-1) in the absence of added aldehyde. The altered ability to express...

The gene encoding N,N'-diacetylchitobiase (chitobiase) of the chitinolytic marine bacterium Vibrio harveyi has been isolated. While expression of the chitobiase gene (chb) was inducible by N,N'-diacetylchitobiose in V. harveyi, it was expressed constitutively when cloned in Escherichia coli, suggesting that controlling elements are not closely linked to chb. Chitobiase was found in the membrane...

Utilization of natural materials sourced from the sea is very promising. These ingredients can function as antibacterials that are useful in a number fields. This study aims to explore extract cucumber Phylloporus sp. an antibacterial agent for Vibrio alginoliticus and harveyi. The diffusion method was carried out with three treatments starting at doses 500, 1000 1500 mg/L replications each tre...