Use of agricultural surpluses for production of biomass by marine microalgae

The marine microalga Phaeodactylum tricornutum was cultivated in semi-continuous culture under mixotrophic conditions with the soluble fractions of potato, rye and wheat flours that had been naturally fermented, at 2% or 4% (w/v). The rye flour produced the highest microalgal cellular density of 90×10⁶ cells.ml^-1 when supplemented with NaNO₃ and NaH₂PO₄. The autotrophic control only gave 57×10⁶ cells.ml^-1. The value of agricultural surpluses, such as rye flour, can therefore be increased by its use in the production of valuable, microalgal biomass which is rich in protein, pigments and fatty acids.     

Twin-screw extrusion of ‘Pesta’-encapsulated biocontrol agents

World Journal of Microbiology and Biotechnology -     

Enhanced endoxylanase production by Myceliophthora thermophila using rice straw and its synergism with phytase in improving nutrition

The goal of the present investigation was to attain the enhanced production of endoxylanase in submerged fermentation using different approaches followed by its utility in improving nutrition of wheat and rice flours along with phytase. Myceliophthora thermophila BJTLRMDU3 produced 51.70 U/mL of xylanase using rice straw as a substrate after optimization with ‘one variable at a time’ approach. After Plackett-Burman design study, sodium nitrate, K₂HPO₄ and Tween 20 were selected as critical factors and further optimized by response surface methodology. Increased xylanase production (80.15 U/mL) was attained with 2.5 % (w/v) sodium nitrate, 1.25 % (w/v) K₂HPO₄, and 2 % (v/v) Tween 20 at 40 °C. An overall 1.5-fold increase in xylanase production was achieved after statistical optimization. Applicability of M. thermophila xylanase (200 U/g flour) alone and in combination with phytase (15 U/g flour) from Aspergillus oryzae SBS50 in wheat and rice flours showed enhancement in nutritional qualities of both flours. About 45.67 %, 29.73 %, and 107.91 % increase in reducing sugars, soluble proteins and inorganic phosphate, respectively in wheat flour, while 94.16 %, 134.52 %, and 473.33 % increase in reducing sugars, soluble proteins and inorganic phosphate, respectively in rice flour was achieved at 60 °C and pH 5.0 by synergistic action of xylanase and phytase as compared to control having only xylanase.     

Effects of caffeine on mating behavior and sperm precedence in Tribolium castaneum

Biogenic amines such as dopamine are physiologically neuroactive substances that affect behavioral and physiological traits in invertebrates, and it has long been known that these substances affect mating behavior in insects. Caffeine is a dopamine activator and thus enhances dopamine receptor activity. However, the effects of caffeine intake on insect mating behavior have been largely unexplored. Therefore, we examined the effect of caffeine on mating behavior in the red flour beetle Tribolium castaneum. Caffeine, which activates dopamine, affected the mating behavior of T. castaneum males. Males who orally ingested caffeine courted faster than males who did not, resulting in faster mounting of females and less time to a male's external aedeagus protrusion. However, the present results showed no difference in sperm precedence measured as a P2 value between males fed caffeine and males not fed caffeine. We discuss the effects of caffeine on insect mating and the possibility that caffeine consumption may cause males to mate with more females in the laboratory.     

Chemical and Nutritional Properties of Hypoallergenic Wheat Flour

The chemical and nutritional properties were investigated of hypoallergenic wheat flour (HWF) prepared by the cellulase-actinase treatment. HWF was composed mainly of oligopeptides and free amino acids, and its average molecular weight was lower than 1,000. Feeding tests on rats showed that, with respect to the PER, GOT and GPT activities and other nutritional indices, the HWF diet was almost equivalent to the control diet which had been prepared from normal wheat flour (NWF). No abnormality was apparent in the main organs after the HWF diet had been fed for 3 weeks. The small intestinal absorption of the HWF diet was found normal by measuring the free amino acid concentration in the intestinal tract and in the portal vein plasma. These data suggest that te absorption of amino acids from the HWF diet was comparable with or more efficient than that from a simulated free amino acid diet.     

Influence of processing and substrate variety on survival and development of Tribolium confusum (Coleoptera: Tenebrionidae)

Tribolium confusum is a major pest of grains and grain products. Some legumes hitherto not used as major food are gaining interest due to increase in human population and the need of food and feeds. Susceptibility of fresh and processed Glycine max and Cajanus cajan flours, and white wheat flour (control) to T. confusum was studied towards effective storage techniques and cheap insect diet. Ten copulating pairs of the beetle were introduced into twenty grams of each flour. Number of eggs laid, emerged larvae, pupae, eclosed adults, and duration of development of each stage was used as indices of survival of T. confusum. Proximate composition, saponin; and α-amylase and protease inhibitors determined suitability of flours as insect diet. This work discusses the significance of proximate composition and anti-nutrient properties in fresh and roasted processed flours on the development and survival of T. confusum.     

Tribolium castaneum as a whole‐animal screening system for the detection and characterization of neuroprotective substances

Parkinson's disease (PD) is a movement disorder caused by the progressive loss of dopaminergic neurons. Natural antioxidants and plant extracts with neuroprotective properties offer a promising new therapeutic approach for PD patients, but a suitable large‐scale screening system is required for their discovery and preclinical analysis. Here we used the red flour beetle (Tribolium castaneum ) as a whole‐animal screening system for the detection and characterization of neuroprotective substances. Paraquat was added to the diet of adult beetles to induce PD‐like symptoms, which were quantified using a novel positive geotaxis behavioral assay. These paraquat‐induced behavioral changes were reduced in beetles fed on diets supplemented with l‐ dihydroxyphenylalanine, ascorbic acid, curcumin, hempseed flour, or the Chinese herb gou‐teng. T. castaneum is, therefore, a valuable model for the screening of neuroprotective substances in chemical libraries and plant extracts and could be developed as a model for the preclinical testing of therapeutic candidates for the treatment of neurodegenerative diseases, such as PD.     

Responses of Tribolium castaneum to olfactory cues from cotton seeds,the fungi associated with cotton seeds,and cereals

We tested, in an olfactometer, whether or not Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) responds preferentially to the volatiles that emanate from the fungi associated with cotton [Gossypium hirsutum L. (Malvaceae)] seed over those that emanate from cereals, because cereals are usually portrayed as the primary resources of these beetles. Pairwise comparisons were conducted between cotton seed, wheat (Triticum aestivum L.), and sorghum [Sorghum bicolor (L.) Moench] (both Poaceae); volatiles were tested from intact seeds and from both water and ethanol extracts. The results demonstrate that T. castaneum is attracted more strongly to cotton seeds with its lint contaminated with fungi, than to the conventional resources of this species (i.e., wheat and sorghum). Further tests prove that it is the fungus on the lint that produces the active volatiles, because the beetles did not respond to sterilized cotton lint (i.e., without the fungi typically associated with it when cotton seed is stored). Tests with five fungal cultures (each representing an unidentified species that was isolated from the field‐collected cotton lint) were variable across the cultures, with only one of them being significantly attractive to the beetles. The others were not attractive and one may even have repulsed the beetles. The results are consistent with the beetles having a strong ecological association with fungi and suggest it would be worth investigating the ecology of T. castaneum from this perspective.     

土壤紧实度变化对小麦籽粒产量和品质的影响

以济南17(强筋品种)、烟农15(中筋品种)、鲁麦22(弱筋品种)为供试品种,设置人为碾压和不碾压2种处理,研究了土壤紧实度(以土壤容重表示)变化对不同类型小麦品种的籽粒产量和加工品质的影响。结果表明,随着土壤紧实度提高,3个品种的分蘖成穗率均显著降低,从而导致单位面积穗数和籽粒产量降低。3个品种相比较分蘖成穗率低的鲁麦22籽粒产量降幅最大。相关品质指标测定结果显示,提高土壤紧实度,对3个品种的蛋白质含量、湿面筋含量、沉淀值和吸水率均无显著影响,但济南17的面筋指数明显降低,面团断裂时间和面团稳定时间显著缩短,单位重量面粉烘焙所得的面包体积变小,而烟农15和鲁麦22受影响较小。其原因可能与土壤紧实度提高条件下济南17籽粒中谷蛋白／醇溶蛋白比例和谷蛋白大聚体含量降低有关。将济南17面团流变学特性年际间变化幅度与紧实度变化的处理效应相比较发现,土壤紧实度是影响强筋小麦品种品质性状稳定性的重要因素之一。