Phytoplankton and Bacterial Communities in South Harbour, Manila Bay, Philippines

In line with the ASEAN-India project “Extent of Transfer of Alien Invasive Organisms in South/Southeast Asia via Shipping”, phytoplankton and bacterial communities in the waters off South Harbour, Manila Bay were investigated. Sampling was done in July and August 2012 and in April and May 2013. A total of 67 phytoplankton species including 29 diatoms and 38 dinoflagellates were identified. Potentially toxic Pseudo-nitzschia spp. were among the diatoms found as well as dinoflagellates Alexandrium spp., and Gymnodinium spp. The diatom Skeletonema costatum appeared to be the dominant species in July and August 2012, whereas Chaetoceros spp. constituted over 85% of the total phytoplankton assemblage in April and May 2013. Mean bacterial abundance ranged from 9.53 x 102–3.18 x 105 cells/mL in July 2012. In addition, 93 bacterial isolates were  identified using 16S rDNA, several of which belonged to the following phyla: Actinobacteria, Bacteriodetes,  Firmicutes, and Proteobacteria; whereas, others were determined as uncultured bacterial clones. These results will serve as a valuable baseline for future studies on phytoplankton and bacterial community structure in Manila Bay

Understanding our seas: National Institute of Oceanography, Goa

The present article summarizes the research done at the CSIR–National Institute of Oceanography in 2014 in ocean science, resources and technology. Significant research has been conducted on air–sea interactions and coastal circulation, biogeochemistry, biology, marine geophysics, palaeoceanography, marine fishery, gas hydrates and wave energy. Technological advances covered topics like oceanographic tools. Major strides have been made in marine resources research and evaluation

Understanding our seas: National Institute of Oceanography, Goa

The present article summarizes the research done at the CSIR–National Institute of Oceanography in 2014 in ocean science, resources and technology. Significant research has been conducted on air–sea interactions and coastal circulation, biogeochemistry, biology, marine geophysics, palaeoceanography, marine fishery, gas hydrates and wave energy. Technological advances covered topics like oceanographic tools. Major strides have been made in marine resources research and evaluation

Characterization of Bacteria in Ballast Water Using MALDI-TOF Mass Spectrometry

To evaluate a rapid and cost-effective method for monitoring bacteria in ballast water, several marine bacterial isolates were characterized by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Since International Maritime Organization (IMO) regulations are concerned with the unintended transportation of pathogenic bacteria through ballast water, emphasis was placed on detecting species of Vibrio, enterococci and coliforms. Seawater samples collected from the North Sea were incubated in steel ballast tanks and the presence of potentially harmful species of Pseudomonas was also investigated. At the genus-level, the identification of thirty six isolates using MALDI-TOF MS produced similar results to those obtained by 16S rRNA gene sequencing. No pathogenic species were detected either by 16S rRNA gene analysis or by MALDI-TOF MS except for the opportunistically pathogenic bacterium Pseudomonas aeruginosa. In addition, in house software that calculated the correlation coefficient values (CCV) of the mass spectral raw data and their variation was developed and used to allow the rapid and efficient identification of marine bacteria in ballast water for the first time

Properties of an alkali-thermo stable xylanase from Geobacillus thermodenitrificans A333 and applicability in xylooligosaccharides generation

An extracellular thermo-alkali-stable and cellulase-free xylanase from Geobacillus thermodenitrificans A333 was purified to homogeneity by ion exchange and size exclusion chromatography. Its molecular mass was 44 kDa as estimated in native and denaturing conditions by gel filtration and SDS-PAGE analysis, respectively. The xylanase (GtXyn) exhibited maximum activity at 70 °C and pH 7.5. It was stable over broad ranges of temperature and pH retaining 88 % of activity at 60 °C and up to 97 % in the pH range 7.5–10.0 after 24 h. Moreover, the enzyme was active up to 3.0 M sodium chloride concentration, exhibiting at that value 70 % residual activity after 1 h. The presence of other metal ions did not affect the activity with the sole exceptions of K+ that showed a stimulating effect, and Fe2+, Co2+ and Hg2+, which inhibited the enzyme. The xylanase was activated by non-ionic surfactants and was stable in organic solvents remaining fully active over 24 h of incubation in 40 % ethanol at 25 °C. Furthermore, the enzyme was resistant to most of the neutral and alkaline proteases tested. The enzyme was active only on xylan, showing no marked preference towards xylans from different origins. The hydrolysis of beechwood xylan and agriculture-based biomass materials yielded xylooligosaccharides with a polymerization degree ranging from 2 to 6 units and xylobiose and xylotriose as main products. These properties indicate G. thermodenitrificans A333 xylanase as a promising candidate for several biotechnological applications, such as xylooligosaccharides preparation

Crystal Structure of Albaflavenone Monooxygenase Containing a Moonlighting Terpene Synthase Active Site*

Albaflavenone synthase (CYP170A1) is a monooxygenase catalyzing the final two steps in the biosynthesis of this antibiotic in the soil bacterium, Streptomyces coelicolor A3(2). Interestingly, CYP170A1 shows no stereo selection forming equal amounts of two albaflavenol epimers, each of which is oxidized in turn to albaflavenone. To explore the structural basis of the reaction mechanism, we have studied the crystal structures of both ligand-free CYP170A1 (2.6 Å) and complex of endogenous substrate (epi-isozizaene) with CYP170A1 (3.3 Å). The structure of the complex suggests that the proximal epi-isozizaene molecules may bind to the heme iron in two orientations. In addition, much to our surprise, we have found that albaflavenone synthase also has a second, completely distinct catalytic activity corresponding to the synthesis of farnesene isomers from farnesyl diphosphate. Within the cytochrome P450 α-helical domain both the primary sequence and x-ray structure indicate the presence of a novel terpene synthase active site that is moonlighting on the P450 structure. This includes signature sequences for divalent cation binding and an α-helical barrel. This barrel is unusual because it consists of only four helices rather than six found in all other terpene synthases. Mutagenesis establishes that this barrel is essential for the terpene synthase activity of CYP170A1 but not for the monooxygenase activity. This is the first bifunctional P450 discovered to have another active site moonlighting on it and the first time a terpene synthase active site is found moonlighting on another protein