No abstract

An extracellular lipase produced by marine fish intestinal isolate Halobacillus sp. AP-MSU 8 was purified and characterized. The lipase was purified to homogeneity using ammonium sulphate precipitation, DEAE-Sepharose anion exchange chromatography and Sephadex G-75 gel filtration chromatography. The overall purification protocols resulted in 25 % yield of lipase with 10.6-fold. The SDS-PAGE (12 %) analysis of purified lipase resulted in the molecular mass of the purified lipase as 25-kDa. The optimum pH and temperature required for maximum activity of purified lipase was 9.0 and 40°C respectively. Also, this lipase is halo tolerant and requires 2.5 M NaCl for maximum activity. The activity of the purified lipase was more in the presence of BaCl 2 and MgSO 4 , and in contrast the enzyme activity was totally inhibited in the presence of ZnSO 4 and ZnCl 2 . The surfactants such as polyethylene glycol and Tween 20 enhanced the lipase activity. Likewise 10 % concentration of organic solvents such as benzene and acetone stimulated the lipase activity, whereas at 20 % concentration all the tested solvents inhibited the lipase activity.

A restrained dominating set [Formula: see text] is said to be a strong restrained dominating set of G if every vertex [Formula: see text] is adjacent to a vertex [Formula: see text] and [Formula: see text]. The minimum cardinality of a strong restrained dominating set of G is said to be the strong restrained domination number of [Formula: see text] and it is denoted by [Formula: see text]. We characterize all the trees with [Formula: see text]. We show that if [Formula: see text] is a tree of order [Formula: see text], then [Formula: see text] and characterize the extremal trees by achieving this lower bound. Simulation was carried out for the strong restrained domination number of Cartesian, strong and lexicographic product under four different network topologies and it was noted that [Formula: see text] under these four network topologies. Furthermore, the strong restrained domination number of [Formula: see text] and [Formula: see text] for any [Formula: see text] and [Formula: see text] for any [Formula: see text] is determined.