SummaryThe bulk of the Earth's biosphere is cold (e.g. 90% of the ocean's waters are ≤ 5°C), sustaining a broad diversity of microbial life. The permanently cold environments vary from the deep ocean to alpine reaches and to polar regions. Commensurate with the extent and diversity of the ecosystems that harbour psychrophilic life, the functional capacity of the microorganisms that inhabitat the cold biosphere are equally diverse. As a result, indigenous psychrophilic microorganisms provide an enormous natural resource of enzymes that function effectively in the cold, and these cold‐adapted enzymes have been targeted for their biotechnological potential. In this review we describe the main properties of enzymes from psychrophiles and describe some of their known biotechnological applications and ways to potentially improve their value for biotechnology. The review also covers the use of metagenomics for enzyme screening, the development of psychrophilic gene expression systems and the use of enzymes for cleaning.

No abstract

Xylanase is the key enzyme that involves in the hydrolysis of xylan, the main constituent of the complex hemicellulose of the plant cell wall. In this study, forty actinomycetes that were isolated from the sediment of Kuantan Mangrove Forest, Malaysia, were tested for their ability to produce extracellular xylanase. At least 15 isolates were able to degrade xylan in the primary agar-based screening on marine agar containing 0.1% (v/v) azo-xylan (Birchwood). The degradation of xylan was indicated by the formation of halo zone around the colonies and the clear zone index (CZI) was calculated as a ratio of the clearing zones to the colony size. Isolate K2-04 with CZI 3.35 ± 1.91 was identified through 16S rRNA study as Verrucosispora sp. This isolate was further grown in marine broth and incubated at 30 °C, 200 rpm for 20 days. The growth of K2-04 and the xylanase activity was measured at day 2, 4, 6,12 and 18 respectively. The highest enzyme activity of the crude enzyme was recorded at day 18 (1.836 U/mL) and exhibited stability after 20 days storage at 4°C. This study serves as a preliminary study to characterize the properties of Verrucosispora sp. K2-04, rare actinomycete of Kuantan Mangrove Forest, Malaysia.  Index Terms-marine Actinomycetes, xylanase, mangrove, Verrucosispora containing 1 g of dried sediment and 9 ml of sterilized sea water was heated in a water bath at 60°C for 20 min. Morphological differences among the isolates were

Roseovarius sp. strain PS-C2 is a bacterium that was isolated from Sekinchan Beach in Selangor, Malaysia, using an ex situ cultivation technique. Here, we present a high-quality annotated draft genome of strain PS-C2 and suggest potential applications of this bacterium.