Biodegradation of the pyrethroid pesticide cyfluthrin by the halophilic bacterium Photobacterium ganghwense isolated from coral reef ecosystem

A halophilic bacterial strain T14 isolated from the mucus of coral Acropora sp. was found to be highly effective in degrading the pyrethroid pesticide, cyfluthrin. T14 was identified as Photobacterium ganghwense (GenBank Accession No. MT360254) based on phenotypic and biochemical characteristics as well as by 16S rRNA gene sequence analysis. The pyrethroid degrading efficiency of P. ganghwense T14 strain was examined under different culture conditions. It was observed that P. ganghwense T14 was able to utilise cyfluthrin as a sole carbon source and was found to grow on mineral medium with pesticide concentrations ranging from 10 to 100 mg l-1. Optimal temperature and pH conditions for efficient cyfluthrin degradation by P. ganghwense T14 were determined as 30° C and 8 respectively. Degradation of cyfluthrin by P. ganghwense T14 was quantitated by gas chromatography-tandem mass spectrometry (GC-MS/MS). Mineral medium supplemented with 100 mg l-1 cyfluthrin and inoculated with P. ganghwense T14 (106 cells ml-1) recorded 92.13% pesticide decomposition within 120 h. Cytotoxicity assay on a fish cell line EM4SpEx derived from the grouper Epinephelus malabaricus, revealed a drastic reduction in cyfluthrin toxicity as evidenced by reduction in the intensity of cell destruction as well as morphological changes when exposed to P. ganghwense T14 treated filtrate, in comparison with that of parent cyfluthrin filtrate. Results of the study clearly indicated potential bioremediative use of P. ganghwense T14 in cyfluthrin contaminated sites.

An idiogram on pachytene bivajents with high resalution multiple bands of Epinephelus malabaricus

Epinephelus malabaricus (Perciformes, Serranidae), a rare marine commercial fish inhabits in the warm-water reef along the southeast coast of China. In the present study, well-spread pachytene bivalents with multiple high-resolution bands were obtained after the testes were treated with a hypotonic alkaline solution and a high-chloroform fixative solution, showing that the number and characteristics of band in each bivalent were stable. According to karyotype analysis, the haploid chromosome set was n=24 (24t), and no heteromorphic bivalent was found. The relative length of the longest and shortest bivalent were 5.86 and 1.66, and the length ratio was 3.53, which was much higher than the length ratio of the exact metaphase mitotic karyotype (1.5) and premetaphase endonuclease karyotype (1.75). An idiogram with 447 bands was constructed, and the zone of each bivalent was divided, respectively. The detailed description of the landmark system and the band positions were preliminary given. This study aims to provide a theoretical reference for the further research on cytogenetics and the physical map construction of chromosome fine frame of E. malabaricus.

Molecular Cloning, Expression and Functional Analysis of Interferon Regulatory Factor 5 (IRF 5) in Malabar Grouper (Epinephelus Malabaricus)

Interferon regulatory factor 5 (IRF5) is known to be involved in the innate immune response and pro-inflammatory cytokines. However, the roles of IRF5 in immune responses in Malabar grouper (Epinephelus malabaricus) have not been extensively explored. In this study, IRF5 gene was identified and characterized from M. grouper. The full-length IRF5 cDNA consisted of a 5’ terminal untranslated region (5’-UTR) of 289 bp and a 3’-UTR of 542 bp, an open reading frame (ORF) of 1500 bp encoding a polypeptide of 499 amino acids with a predicted molecular mass of 56.28 kDa and isoelectric point (pI) of 5.2. The putative MgIRF5 protein consists of four important conserved domains: a helix DNA-binding domain (DBD) at the N-terminus, a middle region, an IRF association domain (IAD) and a virus activated domain (VAD) at the C-terminus. Sequence alignment and phylogenetic analysis showed that highest sequence similarity of IRF5 was observed between the IRF5 genes from Oplegnathus fasciatus and Miichthys miiuy. The mRNA transcripts of IRF5 were detected in a wide range of tissues types from healthy M. grouper with highest expression in muscle, liver and skin. After treatment with poly (I: C), it was significantly up-regulated in spleen and liver tissues. When infected with NNV, the expression level of MgIRF5 was up-regulated in spleen and head kidney and their transcriptional responses to IRF5 increased in the grouper kidney cells. This approach suggests that MgIRF5 is important in the underlying mechanism of the innate immune responses against antiviral response.

ANALISIS PENANGKAPAN IKAN KAKAP MERAH (Lutjanus spp.) DAN KERAPU (Epinephelus sp.) DI PERAIRAN BARRU, SULAWESI SELATAN

Perairan di sekitar Barru Sulawesi Selatan merupakan salah satu kawasan terumbu karang yang penting di Selat Makassar. Sebagian besar dari nelayannya melakukan penangkapan ikan dengan menggunakan rawai dasar dan jaring insang dasar. Analisis perikanan ikan kakap merah (Lutjanus spp.) dan kerapu (Epinephelus sp.) dilakukan pada bulan Agustus dan Oktober 2006 dengan penekanan pada deskripsi alat tangkap dan teknik penangkapannya, komposisi hasil tangkapan, dan beberapa aspek biologi ikan kakap merah dan kerapu. Penelitian ini dilakukan dengan cara mengikuti kegiatan nelayan yang menggunakan rawai dasar dan jaring insang dasar di sekitar terumbu karang dan pencatatan data dari pendaratan ikan utama. Untuk kelengkapan data dilakukan wawancara dengan nelayan dan pedagang pengumpul setempat. Hasil penelitian ini menunjukan daerah penyebaran ikan kakap merah dan kerapu terdapat di perairan Barru dan Pangkajene Kepulauan. Pada perairan yang relatif dangkal (<50 m) digunakan pancing ulur dengan satu atau dua mata pancing (nomor 6 atau 7). Jaring insang dasar digunakan di luar daerah karang, satu pis (tinting) mempunyai panjang 40 m dan dalam 5 m dengan ukuran mata jaring 4 inci. Satu unit jaring terdiri atas 60 pis. Di perairan yang lebih dalam (lebih dari 50) digunakan rawai dasar yang terdiri atas 600 mata pancing (nomor 7 atau 8). Lama trip penangkapan tiga hari. Diperoleh laju pancing pada rawai dasar berkisar 6-8% dan laju tangkap jaring insang dasar berkisar antara 40-60 kg/kapal/tiga hari. Komposisi hasil tangkapan didominansi (47,2%) oleh ikan kakap merah (famili Lutjanidae) yang terdiri atas jenis Lutjanus malabaricus, Lutjanus hyselopterus, Lutjanus sebae, Lutjanus vittus, dan Pinjalo pinjalo. Ikan kerapu (famili Serranidae) terdiri atas jenis Epinephelus areolatus, Epinephelus malabaricus, Epinephelus microdon, dan Plectropomus maculatus. Kecuali itu tertangkap juga ikan lencam (famili Lethrinidae). Pengamatan biologi jenis ikan Lutjanus malabaricus dan Epinephelus malabaricus yang merupakan hasil tangkapan dominan masing-masing diperoleh nilai modus panjang cagak 48 dan 56 cm dengan modus bobot masing-masing 1,8 dan 2,15 kg. Karakteristik pertumbuhan kedua jenis tersebut adalah allometrik positif.The sea waters around Barru, South Sulawesi is one of the coral reef parts in Makassar Strait. Most of the fishermen use fishing lines, bottom long lines, and bottom gill nets in their fishing activities. Analysis of red snappers (Lutjanus spp.) and groupers (Epinephelus sp.) fisheries in this area were carried out in August and October, 2006. The emphasis is focused on the discription of fishing gear and fishing technique, catch composition, and some of biological aspect of red snappers and groupers. The research was done by following the fishing operations of bottom long line and bottom gill net conducted by fishers in the waters around coral reefs. Data were recorded in some importantant landing place at Barru, and interview of some fishermen to complete data and information needed. The result showed that the distribution of red snapper and groupers occured in the waters around Barru and Pangkajene Islands. In the shallow waters (<50 m) the fishermen use a lightly weighted hand line, with one or two relativelly small hooks (nomor 6 or 7). Bottom gill nets are frequently used in shallow back reef areas with one piece of 40 m in length, and 5 m in depth, with mesh size of 4 inches. One unit of the gear consisted of 60 piece of the nets. Meanwhile, in deeper waters (50-150 m), the number of hooks (nomor 7 or 8) in bottom long line operated 600 hooks for each unit. All fishing gears usually have three days at sea for a fishing trip. The average of catch rate (hook rate) for a trip of bottom long line was 6-8% (6 or 8 individual fish for 100 hooks). Meanwhile, the catch rate of bottom jaring insang was about 40-60 kgs/boat/3 days trip. The catches were dominated by the family Lutjanidae in which the red snappers species (reached to 47.2% at this survey period) including Lutjanus malabaricus, Lutjanus hyselopterus, Lutjanus sebae, Lutjanus vittus, and Pinjalo pinjalo. Meanwhile the groupers (family Serranidae) were dominated by species of Epinephelus areolatus, Epinephelus malabaricus, Epinephelus microdon, and Plectropomus maculatus. Other groups were emperors (Lethrinidae) and Gymnocranius. The biological measured for Lutjanus malabaricus and Epinephelus malabaricus as a dominant landed showed the modus of length were 48 and 58 cmFL, respectivelly. Meanwhile the modus of weight were 1.8 and 2.35 kg. The growth characteristic of both species were positive allometric. It means that increasing the weight was faster than their length.