Bio-augmentation of heterotrophic bacteria in biofloc system improves growth, survival, and immunity of Indian white shrimp Penaeus indicus.

Effect of bio-augmentation of Bacillus spp in biofloc on growth, survival and immunity in Indian white shrimp Penaeus indicus was evaluated. Nine Bacillus strains were isolated and screened individually as well as in the form of a consortia. To maintain a C:N ratio of 12:1 a blend of carbohydrate sources was used. Bio-augmentation with bacterial consortium and Virgibacillus sp. produced improved growth and immunity. Shrimp survival ranged from 80 to 95% among treatments. Production was higher (35%) in the biofloc tanks with an average body weight (ABW) of 10.89 ± 1.2 g. On evaluating the immune responses, it was found that trypsin significantly (P < 0.05) enhanced Prophenoloxidase (PO) activity in Lysinibacillus, Bacillus cereus, Bacillus licheniformis and Bacillus subtilis bio-augmented groups. Laminarin induced PO activity was observed in groups supplemented with Oceanobacillus sp., Bacillus sp.and Bacillus megaterium. The lysozyme (LZ) activity was significantly (P < 0.05) higher in B. cereus and Microbial Consortia (MC), while other treatments were less effective. Total hemocyte count (THC) significantly (P < 0.05) increased in all treatment groups compared to the control. Hyaline hemocyte (HH) count was significantly (P < 0.05) higher in the control group (14.43%). Semi granular hemocytes (SGH) was higher in groups treated with Lysinibacillus, Bacillus sp., B. licheniformis and B. subtilis. The granular hemocyte (GH) count was significantly (P < 0.05) higher in Virgibacillus sp., B. cereus, B.megaterium and Oceanobacillus sp. The biofloc alone (BF), treated and augmented with B. megaterium significantly (P < 0.05) increased phagocytic activity. Highly significant phagocytic index (PI) was observed in bio-augmented groups, BF and MC. The relative expression levels of immune genes were found to be significantly up-regulated in shrimps grown in bio-augmented groups. Enhanced immunological parameters implies that bio-augmentation of biofloc with Bacillus spp. improved immunity in shrimps. Hence, bio-augmentation of probiotics in biofloc may be useful in improving culture conditions to produce P. indicus.

First Report of a Complete Genome Sequence of White spot syndrome virus from India.

White spot syndrome virus is a major pathogen of shrimp, causing economic loss to the aquaculture industry. For the first time, a complete de novo genome of an Indian isolate of this virus has been deciphered using Illumina and Nanopore sequencing technologies. The genome has 280,591 bp with 442 predicted coding genes.

Gene expression profiling in gill tissues of White spot syndrome virus infected black tiger shrimp Penaeus monodon by DNA microarray.

White spot syndrome virus (WSSV) continues to be the most devastating viral pathogen infecting penaeid shrimp the world over. The genome of WSSV has been deciphered and characterized from three geographical isolates and significant progress has been made in developing various molecular diagnostic methods to detect the virus. However, the information on host immune gene response to WSSV pathogenesis is limited. Microarray analysis was carried out as an approach to analyse the gene expression in black tiger shrimp Penaeus monodon in response to WSSV infection. Gill tissues collected from the WSSV infected shrimp at 6, 24, 48 h and moribund stage were analysed for differential gene expression. Shrimp cDNAs of 40,059 unique sequences were considered for designing the microarray chip. The Cy3-labeled cRNA derived from healthy and WSSV-infected shrimp was subjected to hybridization with all the DNA spots in the microarray which revealed 8,633 and 11,147 as up- and down-regulated genes respectively at different time intervals post infection. The altered expression of these numerous genes represented diverse functions such as immune response, osmoregulation, apoptosis, nucleic acid binding, energy and metabolism, signal transduction, stress response and molting. The changes in gene expression profiles observed by microarray analysis provides molecular insights and framework of genes which are up- and down-regulated at different time intervals during WSSV infection in shrimp. The microarray data was validated by Real Time analysis of four differentially expressed genes involved in apoptosis (translationally controlled tumor protein, inhibitor of apoptosis protein, ubiquitin conjugated enzyme E2 and caspase) for gene expression levels. The role of apoptosis related genes in WSSV infected shrimp is discussed herein.

3,3'-[(4-Nitro-phen-yl)methyl-ene]bis-(4-hy-droxy-2H-chromen-2-one).

The molecular conformation of the title compound, C(25)H(15)NO(8), is stabilized by strong intramolecular O-H⋯O hydrogen bonds, resulting in the formation of S(1) (1)(7) ring motifs. In the crystal, π-π stacking inter-actions are observed between adjacent nitrobenzene and pyranone rings with a centroid-centroid distance of 3.513 (12) Å. The dihedral angles between the nitrobenzene ring and the coumarin ring systems are 65.61 (8) and 66.11 (8)° while the coumarin ring systems are inclined at 65.69 (8)°.

Transcript Analysis of White spot syndrome virus Latency and Phagocytosis Activating Protein Genes in Infected Shrimp (Penaeus monodon).

Viral latency has been recently observed to be associated with White spot syndrome virus (WSSV) infection in shrimp. In the present study, shrimp samples (Penaeus monodon) surviving WSSV infection were examined for presence of WSSV in latent phase. Virus latency was observed in shrimp which were either experimentally challenged with WSSV and survived the infection or those which survived the natural infection. Three viral transcripts (ORFs 427, 151, 366) associated with latency were analyzed by real-time PCR. The shrimp surviving the natural WSSV infection on estimation with RT-PCR were found to have low grade of WSSV infection (less than 56 copies of WSSV). All the shrimp samples were RT-PCR negative for structural protein genes of WSSV, VP24 and VP28, indicating that these samples were harboring latent phase virus. RT-PCR of all the shrimp samples which survived WSSV infection revealed amplification of phagocytosis activating protein (PAP) gene (435 bp) with higher gene expression levels in experimentally challenged shrimp when compared to naturally infected shrimp. The expression of PAP in WSSV infected shrimp samples indicates its possible role in host response for resistance against WSSV infection. PAP was cloned and expressed as recombinant protein for protection studies. Shrimp were injected with three doses (5, 15 and 20 µg g(-1) body weight) of recombinant PAP. Relative percent survival of 10 % was observed in shrimp immunized with the dose of 15 µg g(-1) body weight of recombinant PAP. The expression of both WSSV latency associated and PAP genes obtained from shrimp surviving the WSSV infection, indicates the possible role of these genes in host-pathogen interaction.

Fatal re-expansion pulmonary oedema in a mechanically ventilated patient.

Fatal course of re-expansion pulmonary oedema (REPO) is infrequent and very rarely documented in mechanically ventilated patients. We report a case of fatal REPO following tube thoracostomy for a right-sided pneumothorax in an elderly patient of chronic obstructive pulmonary disease (COPD) with respiratory failure on mechanical ventilation.

(Z)-2-(2-Hy-droxy-4-meth-oxy-benzyl-idene)-1-benzofuran-3(2H)-one.

In the title compound, C(16)H(12)O(4), the 1-benzofuran-one unit is in a planar conformation [C-C-C-C = 179.69 (12)°]. The conformation around the C=C double bond [1.3370 (17) Å] is Z. In the crystal, the mol-ecules are stabilized by O-H⋯O (running parallel to the bc plane) and C-H⋯O hydrogen bonds.

Molecular biological characterization and biostimulation of ammonia-oxidizing bacteria in brackishwater aquaculture.

In the present study, molecular methods based on sequencing of clone libraries have been used to provide sequence and the phylogenetic information of ammonia oxidizing bacteria (AOB). Ammonia monooxygenase (amoA) gene, which catalyzed the oxidation of ammonia to hydroxyl amine in the initial rate-determining step of nitrification was targeted for detection and characterization of AOB using gene-specific primers. The amoA genes obtained through the clone library construction are closely affiliated with Nitrosomonas sp. and other uncultured beta proteobacteria. The levels of nucleotide similarity and amino acid similarity ranged from 85-99% and 83-88%, respectively. The level of conservation of the amino acid sequences is 73%. The use of a matrix prepared from abundantly available lignocellulosic agrowaste-bagasse has successfully been demonstrated for biostimulation of AOB in aquaculture environment by supplementing nutritional requirement facilitating the biofilm mode of growth of the autotrophic consortia. Present study is useful in predictability and reliability of the treatment of ammonia in brackishwater aquaculture.