Heavy metals biosorption by urease producing Lysinibacillus fusiformis 5B

Biosorption is the ability of biological materials to accumulate heavy metals from wastewater through mediated or physico-chemical pathways of uptake. Urease producing bacteria have been hypothesized to have inherent bioremediation abilities. The aim of this research was to determine the potential of Lysinibacillus fusiformis 5B to biosorp Pb, Cr, Cd and Ni. The stock solution of Pb, Cr, Cd and Ni was prepared by dissolving 0.0157 g of Pb(C2H3O2)2, 0.057 g of K2Cr2O7, 0.018 g of CdSO4 and 0.026 g of NiSO4 in 100 mL of dH2O respectively. Lysinibacillus fusiformis 5B was screened for the potential to utilise 5 ppm of the heavy metals using agar dilution method. Broth of L. fusiformis 5B was inoculated to 10, 15, 20 and 50 ppm of the heavy metals. The rate of biosorption was determined by atomic absorption spectroscopy (AAS) after 0, 7, 14, 21, 28 and 35 days. The biosorption % was determined by Beer Lambart’s equation. Lysinibacillus fusiformis 5B was able to tolerate 5 ppm concentration of all the heavy metals by showing visible growth on surfaces of nutrient agar Petri plates. Generally, there was an increase in biosorption rate as the days progress. After 35 days of incubation, the highest biosorption rate of 99.96%, 99.97%, and 99.94% were recorded for Pb, Cr, and Cd respectively at 10 ppm and 99.33% of Ni at 15 ppm. The results of this study showed that L. fusiformis 5B possess the capacity to biosorp Pb, Cr, Cd and Ni and can be developed as biosorption agent for these heavy metals. DOI: http://dx.doi.org/10.5281/zenodo.402316

Development and dynamic simulation of single screw extruder for the production of cassava and yam starch nanocomposites

A research was conducted to develop a single screw extruder from a locally available material for the mixing and homogenization of bulk solids, such as the composites of cassava and yam starch-glycerol with nanoparticles. The design was made by computing the hopper outlet size, shaft diameter, screw geometry, barrel volume and the capacity of the conveyor, empirically. The stresses in the conical section of the hopper were also evaluated to assess its load requirement, thus avoiding any problem associated with the flow of materials through the hopper opening. The extruder was dynamically simulated to assess its throughput at the feeding, compression and metering zones. This was done by investigating the dynamic effect of the time of operation, with respect to the linear displacement, velocity and power, from the practical motion of the moving auger by Computational Fluid Dynamics method. The results show that the vertical pressure acting downwards and the shear stress within the section were 37.02 kPa and 6.44 kPa. The shaft diameter and screw geometry, which includes screw pitch and angle, were 20 mm, 56 mm and 16.54o. The capacity of the extrusion conveyor and its power requirement were respectively, 18.46 tons/hour and 2.04 kW. The maximum linear displacement and velocity occur at the compression zone at every 3.03 rev/sec, which cause the bulk solid materials to melt, and are pushed by the resulting pressure into the metering zone. The relationship between the linear displacement and the time of operation obeys the power law. Consequently, a 5 Hp electric motor was selected to power the single crew extruder

Response Surface Optimization for Microwave-Assisted Alkaline Pretreatment of Plantain Pseudostem Biomass for Bioethanol Production

Bioethanol is a better alternative to gasoline because its combustion releases little or no dangerous gases to the environment and it is produced from renewable feedstock. However, the availability of bioethanol at commercial level is limited by factors such as the recalcitrant nature of the feedstock as well as the cost of the hydrolytic enzyme. In this study, microwave-assisted alkaline pretreatment was optimized via Box-Behnken experimental Design in Design expert software version 11 to effectively remove lignin from plantain pseudostem. The structure of plantain pseudostem pretreated at optimal conditions were characterized using FTIR, XRD, and SEM. Statistical and regression analysis on the experimental outcomes revealed that the lignin removal follows 2FI model with R2 value of 0.9601, adjusted R2 values of 0.9361 and predicted R2 value of 0.8516; the cellulose content follows 2FI with R2 value of 0.9616, adjusted R2 values of 0.9386 and predicted R2 value of 0.9094; the hemicellulose content followed quadratic model with R2 value of 0.9591, adjusted R2 values of 0.9065and predicted R2 value of 0.8463. The high adequate precision values of cellulose (42.33), lignin removal (23.58) and hemicellulose (15.87) shows that the developed models are true representation of the experimental study. The XRD, FTIR and SEM results of the treated plantain demonstrated that microwaveassisted alkaline pretreatment is effective in removing the recalcitrant nature of lignin. This can be a relatively cheaper feedstock for the production of bioethanol

Optimization of Lignin–Cellulose Nanofiber-Filled Thermoplastic Starch Composite Film Production for Potential Application in Food Packaging

The optimization of the production of thermoplastic starch (TPS) bionanocomposite films for their potential application in food packaging was carried out, according to the Box–Wilson Central Composite Design (CCD) with one center point, using Response Surface Methodology (RSM) and fillers based on lignin and nanofiber, which were derived from bamboo plant. The effects of the fillers on the moisture absorption (MAB), tensile strength (TS), percent elongation (PE) and Young’s modulus (YM) of the produced films were statistically examined. The obtained results showed that the nanocomposite films were best fitted by a quadratic regression model with a high coefficient of determination (R2) value. The film identified to be optimum has a desirability of 76.80%, which is close to the objective function, and contained 4.81 wt. % lignin and 5.00 wt. % nanofiber. The MAB, TS, YM and PE of the identified film were 17.80%, 21.51 MPa, 25.76 MPa and 48.81%, respectively. The addition of lignin and cellulose nanofiber to starch composite was found to have reduced the moisture-absorption tendency significantly and increased the mechanical properties of the films due to the good filler/matrix interfacial adhesion. Overall, the results suggested that the produced films would be suitable for application as packaging materials for food preservation

Heavy metals biosorption by urease producing Lysinibacillus fusiformis 5B

Biosorption is the ability of biological materials to accumulate heavy metals from wastewater through mediated or physico-chemical pathways of uptake. Urease producing bacteria have been hypothesized to have inherent bioremediation abilities. The aim of this research was to determine the potential of Lysinibacillus fusiformis 5B to biosorp Pb, Cr, Cd and Ni. The stock solution of Pb, Cr, Cd and Ni was prepared by dissolving 0.0157 g of Pb(C2H3O2)2, 0.057 g of K2Cr2O7, 0.018 g of CdSO4 and 0.026 g of NiSO4 in 100 mL of dH2O respectively. Lysinibacillus fusiformis 5B was screened for the potential to utilise 5 ppm of the heavy metals using agar dilution method. Broth of L. fusiformis 5B was inoculated to 10, 15, 20 and 50 ppm of the heavy metals. The rate of biosorption was determined by atomic absorption spectroscopy (AAS) after 0, 7, 14, 21, 28 and 35 days. The biosorption % was determined by Beer Lambart’s equation. Lysinibacillus fusiformis 5B was able to tolerate 5 ppm concentration of all the heavy metals by showing visible growth on surfaces of nutrient agar Petri plates. Generally, there was an increase in biosorption rate as the days progress. After 35 days of incubation, the highest biosorption rate of 99.96%, 99.97%, and 99.94% were recorded for Pb, Cr, and Cd respectively at 10 ppm and 99.33% of Ni at 15 ppm. The results of this study showed that L. fusiformis 5B possess the capacity to biosorp Pb, Cr, Cd and Ni and can be developed as biosorption agent for these heavy metals. DOI: http://dx.doi.org/10.5281/zenodo.402316

Protein quality of four indigenous edible insect species in Nigeria

Food security is a serious concern particularly for developing countries. To overcome hunger and malnutrition there is a need for increased research towards finding alternative and cheaper sources of nutrients. Insects have been reported to be rich in protein and could be alternative sources of protein. This work was therefore designed to determine the protein quality of moth caterpillar, termite, cricket and grasshopper and the effects of diets supplemented with these insects on some biochemical and haematological indices of rats. The amino acid compositions of the insects were determined using standard analytical methods. Five iso-nitrogenous and isocaloric diets were formulated on a 10% protein basis with the insects and casein. A Nitrogen free diet was also formulated as control. Thirty six (36) young weanling albino rats (21–28 days old) were divided into 6 groups and fed with the diets ad libitum for 28 days. Their weekly weight gain and daily feed intake were recorded, urine and faeces were collected for nitrogen determination using Kjedahl method and the data obtained used to calculate the various protein quality indices. After the feeding trial periods, the rats were sacrificed, blood samples collected and organs excised for various analyses. Cricket was found to have the highest amino acid score (0.91), protein efficiency ratio (1.78), net protein ratio (3.04) biological value (93.02%) and protein digestibility corrected for amino acid score (0.73) as compared to other insect proteins analysed. The organ body weight ratios of the liver, spleen, lung and heart of rats placed on the insect supplemented diets were not significantly different (p > 0.05) from those fed with casein and basal diets. Serum total protein concentrations in rats fed with cricket diet were not significantly different (p > 0.05) from those fed casein diet while serum LDL cholesterol concentration was lowest in rats fed cricket diet. The finding in this work that the selected insects are nutritious and safe for consumption may alleviate the fear of entomophagy thereby reducing the overdependence on conventional animal proteins. Keywords: Protein quality, Insect species, Biochemical parameters, Haematological parameters, Entomophag

Microbial conversion of agro-wastes for lactic acid production

Lactic acid (LA) is an organic compound produced via fermentation by microorganisms that can utilize a wide range of carbohydrate sources and has gained relevance in food industries for preservation, pharmaceutical industries as additives, textile industries as mordants and production of cosmetics and bioplastics. In spite of the various applications of lactic acid, its availability is a challenge, especially in developing countries like Nigeria and therefore has to be imported, making it very expensive. One of the core substrates for lactic acid production is glucose. This study focused on the production of lactic acid using reducing sugar from locally sourced agro-wastes (corncob, sugarcane bagasse, plantain peduncle and groundnut shell). Bacteria were isolated from the agro-wastes dumpsite and screened for lactic acid production using De Man Rogosa and Sharpe (MRS) agar. The agro-wastes were pretreated using NaOH and hydrolyzed using cellulase produced from Aspergillus niger. The lactic acid bacteria (LAB) were identified based on their cultural, morphological, biochemical and molecular characteristics. The screened isolates were used for the production of lactic acid in an MRS medium containing the agro-waste hydrolysates as the sole carbon source. The LAB isolate with the best ability for lactic acid production was ascertained using the spectrophotometric method. Eleven (11) isolates were obtained from the agro-wastes dumpsites. Lactiplantibacillus plantarum (accession number OM510300) from plantain peduncle dumpsites had the highest potential for lactic acid production (1.9558 g/L). The study revealed that Nigerian-locally sourced agro-wastes can be developed as an alternative source of reducing sugar for lactic acid production and thus leads to agro-wastes management in the environment

Production of polyhydroxyalkanoate (pha) by pseudomonas aeruginosa (ol405443) using agrowastes as carbon source

The search for cost-effective substrates for the manufacturing of valuable products has led to the use of agrowastes as alternative sources of reducing sugar. Numerous bacteria build up polyhydroxyalkanoates (PHAs) as storage materials. This research aimed to produce PHA from Pseudomonas aeruginosa using agrowastes as carbon sources. The agrowastes (corncob, plantain peduncle and sugarcane bagasse) were treated with 1 % NaOH and analysed. The agrowastes were hydrolysed using cellulase produced by Aspergillus niger isolated from agrowastes dumpsite. The agrowaste hydrolysate was used in place of glucose for PHA production in a submerged fermentation. Nile blue A test and Sudan black test showed positive results for the isolate with a bright orange fluorescence on irradiation with UV light and was identified as Pseudomonas aeruginosa (accession number 0L405443). Sugarcane bagasse gave the highest potential for PHA production with PHA values of 5.86 mg/mL, followed by corn cob (5.29 mg/mL) and the least was obtained in plantain peduncle with a yield of 3.58 mg/mL. The findings using response surface methodology (RSM) for optimization show that all the four factors (carbon source, pH, temperature and incubation time) were statistically significant (P < 0.05) for PHA production. The optimum PHA production was attained under culture conditions of 24 h, 38 °C, pH 6.5, and 3 % carbon source. The PHA produced from 10 L of MSM was quantified to be 10.57 g under these conditions. The study revealed that Pseudomonas aeruginosa 0L405443 is a local bacterial strain utilized for the production of PHA using affordable, sustainable and easily available agrowastes hydrolysate as substrate