Diversity of Secondary Metabolites from Marine Bacillus Species: Chemistry and Biological Activity

Marine Bacillus species produce versatile secondary metabolites including lipopeptides, polypeptides, macrolactones, fatty acids, polyketides, and isocoumarins. These structurally diverse compounds exhibit a wide range of biological activities, such as antimicrobial, anticancer, and antialgal activities. Some marine Bacillus strains can detoxify heavy metals through reduction processes and have the ability to produce carotenoids. The present article reviews the chemistry and biological activities of secondary metabolites from marine isolates. Side by side, the potential for application of these novel natural products from marine Bacillus strains as drugs, pesticides, carotenoids, and tools for the bioremediation of heavy metal toxicity are also discussed.     

Experimental Evaluation of Procedures to Quantify Carbohydrate Carbon in Some Calcareous Soils

Carbohydrates are an important component of soil organic matter, and a method is needed to quantify them, which would be efficient in terms of time and cost. Different extractants and methods were examined in this work for their efficiency to extract carbohydrate C from four calcareous soils. Four extractants (distilled water, 0.5 M potassium sulfate (K₂SO₄), and 0.25 and 0.5 M sulfuric acid (H₂SO₄)) and three incubation methods (shaking for 16 h, heating in an oven (85 °C) for 16 h, and heating in a water bath (85 °C) for 2.5 h) were compared. The results show that significantly more carbohydrate C was extracted from all four soils with oven and water bath heating of the soil–extractant suspensions than with shaking them at room temperature. The efficiency of the extractants decreased in this order: 0.5 M H₂SO₄ > 0.25 M H₂SO₄ > 0.5 M K₂SO₄. The combination of the heated–water bath incubation method with 0.5 M H₂SO₄ as extractant was the most efficient method.     

The effect of participatory forest management on the livelihood and poverty of settlers in a rehabilitation program of degraded forest in Bangladesh

The sal forest is the only plainland forest in Bangladesh, and is of national economic and environmental importance. High population and ever increasing poverty has stimulated exploitation of the forest alarmingly and brought it near extinction. In facing this situation, the Bangladesh Forest Department implemented a participatory management approach, involving the householders living in and around the forests, for forest maintenance and protection. This study examines the effectiveness of practicing participatory forestry on the settlers’ livelihood in the encorached area of the sal forest. The settlers were given degraded and encroached forest land through the program. Two major social forestry models — namely agroforestry and woodlots — are included in the study. Participation in the resettlement increased household income, employment opportunities and financial and non-land assets. It was found that the participatory management regime could attain the sustainability of the forest and accelerate the standard of settlers’ livelihood, hence the program is an efficient management option towards sustainability of the forest resources. These findings suggest that there is a role for extending the approach to rehabilitate other degraded and encroached forest lands in Bangladesh.     

Prediction of macronutrients in plant leaves using chemometric analysis and wavelength selection

Purpose

Fast and real-time prediction of leaf nutrient concentrations can facilitate decision-making for fertilisation regimes on farms and address issues raised with over-fertilisation. Cacao (Theobroma cacao L.) is an important cash crop and requires nutrient supply to maintain yield. This project aimed to use chemometric analysis and wavelength selection to improve the accuracy of foliar nutrient prediction.

Materials and methods

We used a visible-near infrared (400–1000 nm) hyperspectral imaging (HSI) system to predict foliar calcium (Ca), potassium (K), phosphorus (P) and nitrogen (N) of cacao trees. Images were captured from 95 leaf samples. Partial least square regression (PLSR) models were developed to predict leaf nutrient concentrations and wavelength selection was undertaken.

Results and discussion

Using all wavelengths, Ca (R²_CV?=?0.76, RMSE_CV?=?0.28), K (R²_CV?=?0.35, RMSE_CV?=?0.46), P (R²_CV?=?0.75, RMSE_CV?=?0.019) and N (R²_CV?=?0.73, RMSE_CV?=?0.17) were predicted. Wavelength selection increased the prediction accuracy of Ca (R²_CV?=?0.79, RMSE_CV?=?0.27) and N (R²_CV?=?0.74, RMSE_CV?=?0.16), while did not affect prediction accuracy of foliar K (R²_CV?=?0.35, RMSE_CV?=?0.46) and P (R²_CV?=?0.75, RMSE_CV?=?0.019).

Conclusions

Visible-near infrared HSI has a good potential to predict Ca, P and N concentrations in cacao leaf samples, but K concentrations could not be predicted reliably. Wavelength selection increased the prediction accuracy of foliar Ca and N leading to a reduced number of wavelengths involved in developed models.

     

Effects of daily consumption of probiotic yoghurt on inflammatory factors in pregnant women: a randomized controlled trial

Previous studies have shown that inflammatory factors increases in pregnancy and is associated with several complications of pregnancy. The aim of this study was to assess effects of daily consumption of probiotic yoghurt on inflammatory factors in pregnant women. In a randomized clinical trial, seventy primigravid (the first pregnancy) and singleton pregnant women aged 18-30 years were assigned to two groups. Subjects consumed daily 200 g probiotic yoghurt containing Lactobacillus acidophilus La5 and Bifidobacterium animalis BB12 (10(7) CFU g(-1) for each) or 200 g conventional yoghurt for 9 weeks. Fasting blood samples were collected at baseline (28 weeks of gestation) and after intervention (37 weeks of gestation). Inflammatory factors, hs-CRP and TNF-alpha, were measured by Enzyme-linked Immunosorbent Assay (ELISA). Independent t-test was used to compare the two groups after intervention and paired-sample t-test compared variables before and after treatment. The results showed that the probiotic yogurt brought about a decrease in the serum hs-CRP level, from 10.44 +/- 1.56 to 7.44 +/- 1.03 microg mL(-1) (p = 0.041). There was no significant change in the conventional yogurt group in the serum hs-CRP level (12.55 +/- 1.57 to 14.51 +/- 1.62 microg mL(-1), p = 0.202). The probiotic yogurt had no effect on TNF-alpha (from 73.75 +/- 6.59 to 77.91 +/- 5.61 pg mL(-1), p = 0.633). Serum TNF-alpha did not change in the conventional yogurt group (p = 0.134). In conclusion probiotic yogurt significantly decreased hs-CRP in pregnant women but had no effect on TNF-alpha.     

Effect of Nutritional Treatments on Physiological Characteristics and Tuberization of Potato Plants under Hydroponic Sand Culture

Under hydroponic condition, number and size of potato tubers are usually controlled by nutritional factors such as nitrogen (N), phosphorus (P), and pH. The main objective of the present study was to find an appropriate combination of N, P, and pH (with respect to tuber number) under hydroponic sand culture and to evaluate the physiological traits affected by nutrients and pH. A factorial experiment based on completely randomized design with four replications was conducted. Results showed that higher phosphorus concentration for 10 days increased tuber number per plant, but tuberization was not influenced by nitrogen interruption and intermittent reduction of pH. Neither N, P, nor pH treatments affected total nitrogen concentration of potato leaf, stem, and tuber. Higher phosphorus concentration increased the level of endogenous abscisic acid (ABA) and indole-3-acetic acid (IAA), induced tuberization and thereby increased net photosynthesis rate of potato plants.     

From Peasant to Farmer: Transformation of Forest Management in China

Small-scale Forestry - In the past 40 years, China has experienced an unprecedented transformation of the rural society and livelihoods and self-subsistence forest management has...     

Effects of foliar application of calcium chloride and urea on quantitative and qualitative characteristics of pomegranate fruits

The effects of urea and calcium chloride and their combinations on qualitative and quantitative characteristics of pomegranate fruits were studied over 2 years. Aqueous solutions of urea at 0%, 0.5%, 1% and 2% and calcium chloride at 0%, 2% and 4% were applied on two branches of pomegranate (Punica granatum L. cv Malase-Yazdi) at full bloom (FB) and 1 month after full bloom (1MAFB) stages. Urea at concentrations of 1% and 2% significantly increased aril size, fruit length and diameter. Calcium chloride at concentrations of 2% and 4% significantly increased average fruit weight and ascorbic acid (AA) content. Both urea and calcium chloride increased soluble solid content (SSC) at all of the used concentrations. In the first time of spraying, higher level of treatments reduced titratable acidity (TA), but the second time of spraying did not significantly affect the TA.     

Response of African Catfish, Clarias gariepinus, to Different Dietary Protein and Lipid Levels in Practical Diets

This study was conducted to find the optimum level of dietary protein and lipid that could produce the highest growth, best feed utilization, and body composition of African catfish, Clarias gariepinus (9.5–10.3 g). Nine diets (three protein levels × three lipid levels) containing 25, 30, or 35% crude protein (CP) with 6, 9, and 12% lipids were formulated. Fish were fed one of the tested diets at the rate of 5% of body weight for the first 8 wk and 3% for the rest of the study. Diets were offered 6 d a week, twice a day (900 and 1400 h) for 13 wk. Fish growth increased significantly with increasing either protein or lipid levels, and the maximum growth was obtained in fish fed diets containing 30% CP with 12% lipid or 35% CP with 9% lipid. The lowest fish growth was obtained at 25% CP with 6% lipid. The optimum feed intake, feed conversion ratio, energy utilization, protein efficiency ratio, and protein growth rate were also recognized in fish fed the above diets. No significant differences in moisture and ash contents in fish fed diets containing different protein and lipid levels were recorded. The protein and lipid contents in the fish body tended to increase with increasing protein and lipid levels in diets. However, the higher protein contents were obtained in fish fed diets containing 35% CP with 6 or 9% lipid, while the lowest ones were obtained at 25% CP with 6 or 9% lipid. The higher lipid contents were obtained at 30 or 35% CP with 12% lipid, while the lowest ones were obtained at 25 or 35% CP with 6% lipid. The present study indicates that the increase of dietary lipid level has a protein-sparing effect, and the diet containing 30% CP with 12% lipid would be suitable for the optimum growth and effective protein utilization of fingerling African catfish.