Optional tool use: The case of wild bearded capuchins (Sapajus libidinosus) cracking cashew nuts by biting or by using percussors

Tool use in humans can be optional, that is, the same person can use different tools or no tool to achieve a given goal. Strategies to reach the same goal may differ across individuals and cultures and at the intra‐individual level. This is the first experimental study at the intra‐individual level on the optional use of a tool in wild nonhuman primates. We investigated optional tool use by wild bearded capuchins (Sapajus libidinosus) of Fazenda Boa Vista (FBV; Piauí, Brazil). These monkeys habitually succeed in cracking open the mesocarp of dry cashew nuts (Anacardium spp.) by pounding them with stones and/or by biting. We assessed whether availability of a stone and resistance of the nut affected capuchins' choice to pound or to bite the nuts and their rates of success. Sixteen capuchins (1–16 years) received small and large dry cashew nuts by an anvil together with a stone (Stone condition) or without a stone (No‐Stone condition). In the Stone conditions, subjects used it to crack the nut in 89.1% (large nuts) and 90.1% (small nut) of the trials. Nut size significantly affected the number of strikes used to open it. Availability of the stone significantly increased the average percent of success. In the No‐Stone conditions, monkeys searched for and used other percussors to crack the nuts in 54% of trials. In all conditions, age affects percentage of success and number of strikes to reach success. We argue that exclusive use of stones in other sites may be due to the higher abundance of stones at these sites compared with FBV. Since capuchins opened cashews with a tool 1–2 years earlier than they succeed at cracking more resistant palm nuts, we suggest that success at opening cashew nuts with percussors may support the monkeys' persistent efforts to crack palm nuts.     

Variation of Pleurotus ostreatus (Jacq. Ex Fr.) P. Kumm. (1871) performance subjected to differentdoses and timings of nano-urea

Supplementation of the growing substrate by nitrogenous additives has been known to improve the production of oyster mushroom (Pleurotus ostreatus (Jacq. ex Fr.) P. Kumm. (1871)). However, the application of nano-additives has not been reported in such cultivation yet. The study investigated the effect of nano-urea added in two different doses (3 g and 5 g per kg substrate), once (at spawning or after first flush) or twice (at spawning and after first flush) to the growing substrate consisting of wheat straw and spent oyster substrate (1:1, w/w). Results showed that the application of nano-urea once has induced the highest number of mushroom flushes (four flushes) despite the dose applied. Contrarily to early findings, where high doses of nitrogen have caused inhibition of mushroom growth and production, nano-urea application has had better effects when applied twice. With 5 g/kg, it induced the shortest period between the first and the third flush (15 days). With 3 g/kg, it resulted in the highest biological and economic yields at the third flush (332.7 g/bag and 283.1 g/bag respectively), in total (973.4 g/bag and 854.0 g/bag respectively), the highest biological efficiency (109.6%), and pileus diameter/stipe length ratio (2.8). Experimental findings of the current study may be potentially applied at commercial scale.     

Use of Local Raw Materials for the Production of Bacillus sphaericus Insecticide in Ghana

Locally available raw materials were used as fermentation media for the preparation of an effective bacterial insecticide of Bacillus sphaericus in Ghana. The choice of materials for media production was based on their availability, their cost and how well they supported growth and sporulation of the bacterium. The materials used were anchovy (Engraulis encrasicolus), spent grain from breweries, bambara beans (Vigna subterranea), sprout maize (Zea mays) and B. sphaericus strain IAB 881. The larvicidal activities of each final whole culture of the insecticides prepared were evaluated against third and fourth instar larvae of the mosquito species Culex quinquefasciatus. The levels of larvicidal activity exhibited by preparations using the raw materials were similar to those where the bacterium was cultured in a synthetic medium, with median lethal concentrations ranging from 0.30 10- 5 to 0.68 10-6. Cell counts were in the range 11 108 - 36 108 colony-forming units ml-1, and spore counts were between 29 107 and 61 107 ml-1.     

菌糠二次利用栽培黑木耳试验研究

为充分利用营养没有得到充分吸收的栽培过食用菌的废弃菌糠、明确在牡丹江地区再利用食用菌菌糠生产黑木耳的适宜比例,以灵芝和鲍鱼菇的废弃菌糠为试验材料,进行不同配方的对比试验。试验结果表明：黑木耳培养料中灵芝菌糠体积分数为30%时栽培效果最佳,显著优于参入鲍鱼菇菌糠的各种培养料配方（P〈0.01）。因此,可以利用灵芝菌糠废料作为替代料栽培黑木耳使用。     

Alternative methods for disposal of spent laying hens: Evaluation of the efficacy of grinding,mechanical deboning,and of keratinase in the rendering process

Besides the challenges of mortality and litter disposal, the poultry industry must find economical means of disposing of laying hens that have outlived their productive lives. Because spent hens have low market value and disposing of them by composting and burial is often infeasible, finding alternative disposal methods that are environmentally secure is prudent. The feasibility of grinding or mechanically deboning spent hens with and without prior mechanical picking was evaluated for the production of various proteinaceous by-product meals. The end products were analyzed for nutrient content and found to be high in protein (35.3–91.9% CP) and, with the exception of the feathers, high in fat (24.1–58.3%), making them potentially valuable protein and energy sources. After considering physical and economic feasibility, mechanical deboning was determined to be a logical first step for the conversion of spent hens into value-added by-product meals. Because the hard tissue fraction (primarily feathers, bones, and connective tissue) generated by mechanically deboning the hens presents the greatest challenge to their utilization as feedstuffs, attention was focused on technologies that could potentially improve the nutritional value of the hard tissue for use as a ruminant protein source. Traditional hydrolysis of this hard tissue fraction improved its pepsin digestibility from 74% to 85%; however, subsequent keratinase enzyme treatment for 1 h, 2 h, 4 h, or 20 h after steam hydrolysis failed to improve the pepsin or amino acid digestibility any further (P > 0.10). Enzyme hydrolysis did, however, increase the quantities of the more soluble protein fractions (A: 45.5, 46.6, 52.8, 51.6, and 55.8% of CP; B₁: 3.2, 9.8, 6.0, 4.6, and 4.1% of CP; B₂: 11.7, 18.1, 22.8, 29.6, and 22.0% of CP for 0, 1 h, 2 h, 4 h, and 20 h, respectively) and reduced quantities of the less soluble fractions (B₃: 30.2, 18.1, 10.8, 5.5, and 10.2% of CP; C: 9.4, 7.5, 7.6, 8.8, and 7.9% of CP for 0, 1 h, 2 h, 4 h, and 20 h, respectively). The protein digestibility of the steam hydrolyzed hard tissue fraction from the mechanical deboning of spent hens was found to be comparable to the digestibility of feather meal, but post-hydrolysis keratinase treatment did not improve feeding value for ruminants.     

Microbial community structure and dynamics in a mixotrophic nitrogen removal process using recycled spent caustic under different loading conditions

A laboratory-scale Bardenpho process was established to investigate the proper nitrogen loading rate (NLR) when modified spent caustic (MSC) is applied as electron donor and alkalinity source for denitrification. MSC injection induced autotrophic nitrogen removal with sulfur as electron donor and heterotrophic denitrification. The nitrogen removal rate (NRR) did not increase proportionally to NLR. Based on the total nitrogen concentration in the effluent observed in the trials with MSC, the NLR in the influent should not exceed 0.15 kg N/m³ d in order to satisfy water quality regulations. Microbial communities in the anoxic reactors were characterized by pyrosequencing of 16S rRNA gene sequences amplified by the polymerase chain reaction of DNA extracted from sludge samples. Microbial diversity was lower as MSC dosage was increased, and the injection of MSC caused an increase in SOB belonging to the genus Thiobacillus which is responsible for denitrification using sulfur.     

Basic studies and applications on bioremediation of DDT: A review

The persistent insecticide DDT (1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane) has been widely used for pest control in the management of mosquito-borne malaria and is still used for that purpose in some tropical countries. Considering the potential for negative effects due to DDT contamination, it is necessary to determine effective methods of remediation. Several methods have been used to degrade or transform DDT into less toxic compounds. Bacteria and white-rot fungi (WRF) have been shown to enhance the degradation process in soil using both pure and mixed cultures. Recently, a biological approach has been used as an environmentally-friendly treatment, using new biological sources to degrade DDT, e.g. brown-rot fungi (BRF), cattle manure compost (CMC) and spent mushroom waste (SMW). In this review, the abilities of BRF, CMC and SMW to degrade DDT are discussed, including the mechanisms and degradation pathways. Furthermore, application of these sources to contaminated soil is also described. The review discusses which is the best source for bioremediation of DDT.     

Waste biomass of Nostoc linckia as adsorbent of crystal violet dye: Optimization based on statistical model

The potential of spent biomass of a hydrogen producing cyanobacterial strain Nostoc linckia from a hydrogen fermentor was studied for decolorization of a tri-phenylmethane dye, crystal violet. The waste cyanobacterial biomass immobilized in calcium alginate was used as a biosorbent and the process variables were optimized for maximum dye removal using the statistical response surface methodology (RSM). Batch mode experiments were performed to determine the kinetic behavior of the dye in aqueous solution allowing the computation of kinetic parameters. Influence of interacting parameters like temperature (25-35 °C), pH (4-8), initial dye concentration (100-200 mg/L) and cyanobacterial dose (0.2-0.4 g) on dye removal were examined using central composite design (CCD) which included two additional levels for each parameter. Second-order polynomial regression model, was applied which was statistically validated using analysis of variance. Ability of the immobilized biomass to decolorize the dye was maximum (72%) at pH 8.0, temperature 35 °C, 200 mg/L initial dye concentration and 0.2 g cyanobacterial dose. Adsorption of the dye on cell surface was further confirmed by scanning electron micrographs of the biomass before and after dye loading. FT-IR studies revealed that decolorization was due to biosorption mediated mainly by functional groups like hydroxyl, amide, carboxylate, methyl and methylene groups present on the cell surface.     

In situ bacterial colonization of compacted bentonite under deep geological high-level radioactive waste repository conditions

Subsurface microorganisms are expected to invade, colonize, and influence the safety performance of deep geological spent nuclear fuel (SNF) repositories. An understanding of the interactions of subsurface dwelling microbial communities with the storage is thus essential. For this to be achieved, experiments must be conducted under in situ conditions. We investigated the presence of groundwater microorganisms in repository bentonite saturated with groundwater recovered from tests conducted at the Äspö underground Hard Rock Laboratory in Sweden. A 16S ribosomal RNA and dissimilatory bisulfite reductase gene distribution between the bentonite and groundwater samples suggested that the sulfate-reducing bacteria widespread in the aquifers were not common in the clay. Aerophilic bacteria could be cultured from samples run at ≤55°C but not at ≥67°C. Generally, the largely gram-negative groundwater microorganisms were poorly represented in the bentonite while the gram-positive bacteria commonly found in the clay predominated. Thus, bentonite compacted to a density of approximately 2 g cm^?3 together with elevated temperatures might discourage the mass introduction of the predominantly mesophilic granitic aquifer bacteria into future SNF repositories in the long run.     

Co-production of S-adenosyl-l-methionine and glutathione from spent brewer’s yeast cells

Both S-adenosyl-l-methionine (AdoMet) and glutathione (GSH) are important small molecules with pharmaceutical importance. The co-production of AdoMet and GSH using abundant spent brewer’s yeast cells from the beer industry and with l-methionine supplement was successfully realized. Experimental data showed that improvement of GSH productivity was accompanied by AdoMet accumulation. AdoMet productivity of 40–45 mg g⁻¹ (DCW) was successfully achieved and an additional 13–18 mg g⁻¹ (DCW) GSH was synthesized in spent brewer’s yeast cells.