Proceedings of the National Academy of Sciences, India Section B: Biological Sciences

Insect gut microbial community is known to produce biotechnologically important products. Present study is focussed on isolation of bacteria and screening of siderophore producing strains of Sathrophyllia femorata collected from Western Ghats region near Pune, Maharashtra, India (19°20′N and 73°47′E). Total 207 bacteria were isolated from gut of 2 different specimens (DM and EM) of grasshopper belonging to S. femorata. Out of 207 bacterial isolates, 166 (79 %) isolates produced siderophore during their submerged growth in iron deficient succinic acid medium. Among these, 24 isolates produced copious amount of siderophore and hence selected for further study. Further analysis of these isolates showed absorption maxima either at 240 or at 250 nm depending on type of siderophore. Molecular identification of these siderophore producing bacteria based on 16S rRNA gene sequencing confirms their affiliation to 37 species representing 19 genera. Dominance of phylum Proteobacteria followed by Firmicutes was observed. Among 19 genera, gammaproteobacteria like Acinetobacter, Klebsiella and Pseudomonas showed abundance over other genera like Serratia, Stenotrophomonas and Yokenella. Some of these bacteria have been used in plant growth promotion and as biocontrol agents against insect pests of plants. Siderophore producing bacteria having insecticidal activity against the insect pests promoting plant growth can serve as green bioinoculants for sustainable agriculture.

Bacillus sp. PP9, a noble bacterial isolate of mrigal (Cirrhinus mrigala) gut was investigated for its efficacy as a dietary probiotic against mrigal (C. mrigala) through a dose dependent impact assessment. Mrigal fingerlings (avg.wt. 2.5 ± 0.20 g) were fed with three different doses (2 × 104, 2 × 105 and 2 × 106 CFU) of Bacillus sp. PP9 admixed with 100 g feed for a period of 60 days. It was found that the feed with Bacillus concentration of 2 × 104 CFU exhibited significantly higher growth, maximum RNA DNA ratio, lower food conversion ratio in comparison to other two feed types. Enhanced intestinal protease and α-amylase activity followed by maximum hepatic glutamic oxaloacetic transaminase and glutamate pyruvate transaminase levels were also monitored in this specific feed type. Important hematological parameters like hemoglobin percentage, total erythrocyte count, total leukocyte count, corpuscular hemoglobin also indicated a healthy trend in this dose. Furthermore, the same dietary treatment exhibited highest levels of total serum protein, albumin globulin ratio and serum bactericidal activity. The growth, nutrition and immunological parameters showed a declining trend with increase in the bacterial concentration as well as in the control group (without probiotic). In summary, dietary supplement of 2 × 104/100 g appears as a potential probiotic dose of Bacillus sp. PP9 for growth, nutritional efficacy as well as immunological modulation of C. mrigala and denotes a recommended concentration for its future field applications.

Spinetoram 120 SC is an insecticide used against the leafroller, Strepsicrates semicanella (Lepidoptera: Torticidae), in Eucalyptus plantations. Control efficacy in plantations is a difficult issue due in large part to weather. Adjuvants are added to reduce insecticide runoff from the leaf surface. Three adjuvants such as alkyl aryl polyglycol ether 400 g/L (Agristick), mixture of fatty alkyl sulphate and fatty alkyl betaine (CBA Stick 100), and condensate nonylphenolethylene oxide 95 g/L and polyvinyl alcohol 19 g/L (Indostick 100/20 SL) were tested with the insecticide spinetoram 120 SC against S. semicanella. Adjuvant treatments significantly increased the efficacy of spinetoram 120 SC in controlling S. semicanella. The CBA Stick with 3 and 2 ml L−1 reduced S. semicanella incidence best compared to the other treatments at 7 DAT (days after treatment) and 14 DAT. A rain simulation (10 mm) conducted at 30-min intervals after spraying was sufficient to show deterioration in insecticide efficacy. Spinetoram at a dosage of 0.5 ml L−1 with the adjuvant CBA Stick at a dosage of 3 ml L−1 was recorded as the best treatment for S. semicanella at 14 DAT in a simulated rain of 10 mm.

Aedes aegypti, Anopheles subpictus and Culex quinquefasciatus are the principal vector mosquitoes globally, especially in tropical and subtropical countries. It is very essential to control the mosquito population to prevent mosquito-borne disease transmission. The major goal of the present study was to isolate an alternative for the microbial mosquito control agents like Bacillus thuringiensis and Bacillus sphaericus. The spore forming soil bacteria isolated from Burdwan, West Bengal, India were assessed for mosquitocidal potential. One potent mosquitocidal isolate was characterized by phenotypic, biochemical and 16S rDNA sequence (GU244410) analysis. The isolate was identified as Aneurinibacillus aneurinilyticus. Five ml bacterial suspension of A. aneurinilyticus (22 × 109 colony forming unit/milliliter)/100 ml water resulted in 34, 59.6 and 100 % mortality of Ae. aegypti, Cx. quinquefasciatus and An. subpictus larvae respectively within 72 h, whereas, 10 ml suspension having same concentration showed 95 and 97 % death of Ae. aegypti and Cx. quinquefasciatus larvae respectively within the same time period.

Climate change is a long term significant change in average weather of a region. Prominent natural causes of such changes are continental wave, volcanoes, ocean current, earth’s tilt, comets, etc. Prominent human factors leading to such changes are large-scale use of fossil fuels and human migration from rural to urban areas. The small Islands developing states are least in their contribution to climate hazards group but stand first in bearing its brunt. Indian sub-continent has Andaman and Nicobar groups of Islands on east and Lakshadweep on west coast. In the Islands the climate change plays important impact on mangroves, coral reefs, capture and culture fisheries, live stocks and agriculture. There is a need for evolving an ecosystem-centric and location-specific adaptation strategies for these Islands to deal with the climate change in view of landscape, topography, physical isolation from main land and biodiversity richness.

A total of 295 samples from milk (110), kalaari (110), ice-cream (75) were analysed to reveal the prevalence of Listeria species in and around Jammu. The overall prevalence of Listeria species was 8 (2.71 %). Listeria monocytogenes was isolated from 7 samples (2.37 %) which included 3 (2.72 %) in milk, 4 (3.63 %) in kalaari and one isolate of Listeria ivanovii (4.54 %) from ice-cream. The prevalence was higher in winter months (p < 0.05). All isolates of L. monocytogenes (n = 7) and L. ivanovii (n = 1) were hemolytic and Christie, Atkins, Munch-Peterson tests were positive while 5 L. monocytogenes, one L. ivanovii were phosphatidylinositol specific phospholipases C positive. All Listeria isolates were sensitive to Amoxicillin + Sulbactam Ampicillin, Erythromycin and Enrofloxacin, Levofloxacin, Gentamycin and multidrug resistant to Amikacin, Cephalexin, Cefixime, Cefuroxime and Oleandomicin.

Lead (Pb) is one of the major causes of oxidative damage. This study evaluated the effect of Citrullus lanatus (watermelon) seed extract (CLSE) on hematological and oxidative stress biomarkers in rats following exposure to lead. Wistar rats were assigned to 5 groups (n = 5); group 1 Control, group 2 received 120 mg/kg Pb acetate only, group 3 received 200 mg/kg ethanol seed extract of CLSE only, group 4 received Pb acetate and CLSE (120 mg/kg + 200 mg/kg), group 5 received Pb and CLSE (120 mg/kg + 400 mg/kg). Pb caused a decrease (p < 0.05) in red blood cell count and indices, increased white blood cell counts and differential counts when compared with the control and CLSE-treated groups. CLSE administration raised (p < 0.05) RBC counts and reduced total WBCs when compared to control groups. Platelet count in CLSE high dose was comparable to control. Glutathione and superoxide dismutase (SOD) activities decreased (p < 0.05), while malondialdehyde (MDA) was raised (p < 0.05) in Pb-only group when compared with CLSE-treated groups. C. lanatus (watermelon) seed may be beneficial in management of hematological disorders caused by Pb-induced oxidative stress.

Thyroid hormones (THs) play an important role in many physiological functions both in mammalian and non-mammalian vertebrates. The effect of THs is mediated by thyroid hormone receptors, which are members of nuclear hormone receptor super family. cDNA sequence of 816 bp mRNA of Thyroid stimulating hormone receptor (TSHR) was cloned from Clarias batrachus, which encoded a peptide of 272 amino acids. The deduced amino acid sequence showed high similarity to Clarias gariepinus and Ictalurus punctatus. Phylogenetic analysis of C. batrachus deduced amino acid sequence showed more similarity with C. gariepinus and I. punctatus. The qPCR result displayed that TSHR mRNA was highly expressed in brain, testis and ovary. mRNA expression level of TSHR was analysed after administration of three different dosages of sLHRH viz 0.02, 0.03 and 0.050 μg/g body weights respectively at different time points. The TSHR mRNA expression was upregulated both with respect to different dosages (maximum in 0.05 μg/g) and time intervals (maximum after 6 h) in all treatments. The higher expression of TSHR mRNA in gonads and upregulation of THSR mRNA expression level after sLHRH administration clearly shows the positive relation between Thyroid hormones and reproduction in fishes. This is first report of LHRH hormone effect on TSHR at molecular level in fish.

Assessment of soil quality is essential for providing sustainable management strategies in an anthropogenically disturbed forest. The study was conducted in coal mine disturbed forest (CMDF) and undisturbed community forest (UDCF) at the Northern tropical semi-deciduous forest of Nagaland to investigate soil physico-chemical properties and SQI using principal component analysis (PCA). Comparative soil physico-chemical analysis shows CMDF soil has acidic pH (3.58 ± 0.09), reduced organic carbon (1.21 ± 0.03) and low available N (83.47 ± 8.73), available K (161.28 ± 6.37) and total N (0.87 ± 0.05). In both the methods, UDCF presented higher soil quality index with SQIa (UDCF = 1.97, CMDF = 1.61) and SQIw (UDCF = 0.98, CMDF = 0.68). The result exhibits that anthropogenic activities such as deforestation and coal mining in tropical forest can deteriorate soil quality and hamper the rejuvenating soil properties.

Field experiments were conducted with four levels of irrigation and nitrogen on wheat for 2 years (2009–2010 and 2010–2011) to quantify and predict the crop water status using hyperspectral remote sensing. Hyperspectral reflectance in 350–2500 nm range was recorded at five growth stages. Based on highest correlation between relative leaf water content (RLWC) and reflectance in five water bands, the booting stage was identified as the most suitable stage for water stress evaluation. Ten hyperspectral water indices were calculated using the first year booting stage reflectance data and prediction models for RLWC and equivalent water thickness (EWT) based on these ten indices were developed. The prediction models for RLWC based on moisture stress index (MSI), normalized difference infrared index (NDII), normalized difference water index1640 (NDWI1640) and normalized multi-band drought index (NMDI) were identified as the most precise and accurate models as indicated by different validation statistics. The models developed for EWT based on water band index (WBI), MSI, NDWI1640 and NMDI were found to be most suitable and accurate. These indices were found to be insensitive to N stress treatments indicating their ability to detect water deficiency as the cause of plant stress. Thus, the study identified four hyperspectral water indices to assess the wheat crop water status at booting stage and developed their respective predictive models.