Production and characterization of xylanase from a Streptomyces species grown on agricultural wastes

Alkali-treated corn stalk gave maximum xylanase production at supporting growth of Streptomyces HM-15. Xylanase was stable for 24 h over a pH range of 5.0 to 7.0, had optimal activity between 50 and 60°C and a halflife of 5 h at 60°C. Xylanase production and activity were inhibited by xylose.The authors are with Department of Biosciences, Sardar Patel University. Vallabh Vidyanagar-388120, Gujarat, India.     

Selection and characterization of a proteo-chitinolytic strain of Bacillus thuringiensis,able to grow in shrimp waste media

This paper reports the selection and characterization of Bacillus thuringiensis strains, with ability to grow in a proteo-chitinaceous substrate (milled shrimp waste) as the sole ingredient. Selected strains were able to produce crystal proteins, as well as proteases and chitinases as fermentation by-products. By a preliminary, qualitative screening of 152 B. thuringiensis strains, grown on media rich in protein and chitin, eight strains were selected. These strains were cultured in a liquid medium containing milled shrimp waste and their kinetics of protease production were followed. The two most active proteolytic strains (Bt-103 and Bt-112) were characterized by their crystal protein content, plasmid profiles, crystal ultrastructure, and toxicity towards Manduca sexta, Aedes aegypti and Leptinotarsa texana. The only activity recorded in these species was moderate toxicity of strain Bt-112 against Manduca sexta first instar larvae, as well as the highest proteolytic and chitinolytic activities. Its bipyramidal crystals were associated with semi-cuboidal inclusions and although its crystal proteins were similar to those of B. thuringiensis kurstaki (HD-1), its plasmid content was quite different. Serotyping of Bt-112 indicated that it belongs to serovar. tolworthi. Further studies with a similar strategy might render more strains with ability to grow in a rich waste by-product like the shrimp waste, which may show not only higher insecticidal activity, but also with the ability to produce extracellular enzymes with biotechnological applications.     

Modular development enables rapid design of media for alternative hosts

Developing media to sustain cell growth and production is an essential and ongoing activity in bioprocess development. Modifications to media can often address host or product-specific challenges, such as low productivity or poor product quality. For other applications, systematic design of new media can facilitate the adoption of new industrially relevant alternative hosts. Despite manifold existing methods, common approaches for optimization often remain time and labor-intensive. We present here a novel approach to conventional media blending that leverages stable, simple, concentrated stock solutions to enable rapid improvement of measurable phenotypes of interest. We applied this modular methodology to generate high-performing media for two phenotypes of interest: biomass accumulation and heterologous protein production, using high-throughput, milliliter-scale batch fermentations of Pichia pastoris as a model system. In addition to these examples, we also created a flexible open-source package for modular blending automation on a low-cost liquid handling system to facilitate wide use of this method. Our modular blending method enables rapid, flexible media development, requiring minimal labor investment and prior knowledge of the host organism, and should enable developing improved media for other hosts and phenotypes of interest.     

Weekly variation in physical activity of the Oraon agricultural labourers of Jalpaiguri district,West Bengal

The energy expenditure due to habitual physical activity is known to depend on several factors, but possible effects of most of the determinants are not clearly known. The present study deals with weekly variation in energy expenditure of the Oraon agricultural labourers of Jalpaiguri district, West Bengal, India. The results show that, among males, there are significant differences between days of the week. But females do not show any such trend. The possible explanation of the results are the sociocultural practices of the studied population.     

Effect of potting media on the efficacy and dispersal of entomopathogenic nematodes for the control of black vine weevil, Otiorhynchus sulcatus (Coleoptera: Curculionidae)

The effect of five commercial potting media, peat, bark, coir, and peat blended with 10% and 20% compost green waste (CGW) on the virulence of six commercially available entomopathogenic nematodes (EPN), Heterorhabditis bacteriophora UWS1, Heterorhabditis megidis, Heterorhabditis downesi, Steinernema feltiae, Steinernema carpocapsae, and Steinernema kraussei was tested against third-instar black vine weevil (BVW), Otiorhynchus sulcatus. Media type was shown to significantly affect EPN virulence. Heterorhabditis species caused 100% larval mortality in all media whereas Steinernema species caused 100% larval mortality only in the peat blended with 20% CGW. A later experiment investigated the effect of potting media on the virulence of EPN species against BVW by comparing the vertical dispersal of EPN in the presence and absence of BVW larva. Media type significantly influenced EPN dispersal. Dispersal of H. bacteriophora was higher than H. megidis, H. downesi, or S. kraussei in all media, whereas, S. feltiae and S. carpocapsae dispersal was much reduced and restricted to peat blended with 20% CGW and coir, respectively. In the absence of larvae, most of the EPN species remained in the same segment they were applied in, suggesting that the larvae responded to host volatile cues. Greenhouse trials were conducted to evaluate the efficacy of most virulent strain, H. bacteriophora in conditions more representative of those in the field, using 2.5 × 10⁹ infective juveniles/ha. The efficacy of H. bacteriophora UWS1 against third-instar BVW was 100% in peat, and peat blended with 10% and 20% CGW but only 70% in bark and coir, 2 weeks after application. These studies suggest that potting media significantly affects the efficacy and dispersal of EPN for BVW control.     

Activated carbons from flax shive and cotton gin waste as environmental adsorbents for the chlorinated hydrocarbon trichloroethylene

Agricultural by-products represent a considerable quantity of harvested commodity crops. The use of by-products as precursors for the production of widely used adsorbents, such as activated carbons, may impart a value-added component of the overall biomass harvested. Our objective in this paper is to show that flax shive and cotton gin waste can serve as a precursor for activated carbon that can be used for adsorption of trichloroethylene (TCE) from both the liquid and gas phases. Testing was conducted on carbon activated with phosphoric acid or steam. The results show that activated carbon made from flax shive performed better than select commercial activated carbons, especially at higher TCE concentrations. The activation method employed had little effect on TCE adsorption in gas or vapor phase studies but liquid phase studies suggested that steam activation is slightly better than phosphoric acid activation. As expected, the capacity for the activated carbons depended on the fluid phase equilibrium concentration. At a fluid concentration of 2 mg of TCE/L of fluid, the capacity of the steam activated carbon made from flax shive was similar at 64 and 80 mg TCE/g of carbon for the vapor and liquid phases, respectively. Preliminary cost estimates suggest that the production costs of such carbons are $1.50 to $8.90 per kg, depending on activation method and precursor material; steam activation was significantly less expensive than phosphoric acid activation.     

The effect of the substitute media on the development of the potted New Guinea Impatiens (Impatiens hawkeri)

Some kinds of agricultural castoffs such as sawdust (SD) and the powder of coconut coir (PCC) were used as growing media to substitute peat moss for the New Guinea Impatiens. It showed that all the substitute media should fit for the growth of the root system without disturbing the spatial development of the root. The growths of the plants in substitute media are all exceeded that in PM or only below the contrast indistinctly. The comprehensive indexes of plants in PCC and SD are 0.76 and 0.98, and the comprehensive indexes of plants in PSS and PPH are all higher than that in PM. It means that those four kinds of substitutes can be used to take the place of the peat moss totally as soilless growing media. In the period of 50–100 s, the differences of the Ultra-Weak Photon Intensity of the leaves among all the treatments are different significantly, and the trend is similar to that of the root. The photosynthesis of the New Guinea Impatiens is very different to the data of morphology evaluation indexes. There is no noticeable effect of the growing medium itself on the elements contents of the plant. The determinant may be the nutrients solution. There is no significant difference of the contents of chlorophyll in the plant that was planted in the substitute media between the PM. Under almost the same growth conditions, the Hoagland nutrients solution can make a steady and balanced supply of nutrients for the plant which cannot be evidently disturbed by the type of media. The substitute media have lower performance of preserving moisture and fertility, under normal cultivating conditions, the plants developed well, but in order to keep the plant in good condition, the substitute media depends more on extraneous nutrients from nutrients solution than PM.     

Method for the characterization of size-exclusion chromatography media for preparative purification of DNA restriction fragments

A protocol has been developed to characterize the potential of size exclusion chromatography media for the separation of DNA fragments at a preparative scale. A standard DNA mixture composed of -DNA cut with the restriction enzymes, AluI and HaeIII, was chromatographed on a column packed with the gel of interest. Fractions were collected and examined by PAGE. A digitized image of the gel was analyzed with the aid of a computer software program to determine the DNA fractionation range and selectivity curve for each chromatography gel. Four gels were characterized using this protocol. The effect of the elution buffer ionic strength on the fractionation of DNA was also investigated.The US Government right to retain a non-exclusive royalty-freelicense in and to any copyright is acknowledged.     

Particle size distribution of rice flour affecting the starch enzymatic hydrolysis and hydration properties

Rice flour is becoming very attractive as raw material, but there is lack of information about the influence of particle size on its functional properties and starch digestibility. This study evaluates the degree of dependence of the rice flour functional properties, mainly derived from starch behavior, with the particle size distribution. Hydration properties of flours and gels and starch enzymatic hydrolysis of individual fractions were assessed. Particle size heterogeneity on rice flour significantly affected functional properties and starch features, at room temperature and also after gelatinization; and the extent of that effect was grain type dependent. Particle size heterogeneity on rice flour induces different pattern in starch enzymatic hydrolysis, with the long grain having slower hydrolysis as indicated the rate constant (k). No correlation between starch digestibility and hydration properties or the protein content was observed. It seems that in intact granules interactions with other grain components must be taken into account. Overall, particle size fractionation of rice flour might be advisable for selecting specific physico-chemical properties.     

The role of solid waste materials as habitats for macroinvertebrates in a lowland dam reservoir

Eight hypereutrophic phytoplankton dominated ponds from the Brussels Capital Region (Belgium) were biomanipulated (emptied with fish removal) to restore their ecological quality and reduce the risk of cyanobacterial bloom formation. Continuous monitoring of the ponds before and after the biomanipulation allowed the effects of the management intervention on different compartments of pond ecosystems (phytoplankton, zooplankton, submerged vegetation and nutrients) to be assessed. Fish removal resulted in a drastic reduction in phytoplankton biomass and a shift to the clear-water state in seven out of eight biomanipulated ponds. The reduction in phytoplankton biomass was associated with a marked increase in density and size of large cladocerans in six ponds and a restoration of submerged macrophytes in five ponds. The phytoplankton biomass in the ponds with extensive stands of submerged macrophytes was less affected by planktivorous fish recolonisation of some of the ponds later in the summer. The two non-vegetated ponds as well as one pond with sparse submerged vegetation showed a marked increase in phytoplankton biomass associated with the appearance of fish. Phytoplankton biomass increase coincided with the decrease in large Cladocera density and size. One pond lacking submerged macrophytes could maintain very low phytoplankton biomass owing to large Cladocera grazing alone. The results of this study confirmed the importance of large zooplankton grazing and revegetation with submerged macrophytes for the maintenance of the clear-water state and restoration success in hypereutrophic ponds. They also showed that large Cladocera size is more important than their number for efficient phytoplankton control and when cladocerans are large enough, they can considerably restrain phytoplankton growth, including bloom-forming cyanobacteria, even when submerged vegetation is not restored. The positive result of fish removal in seven out of eight biomanipulated ponds clearly indicated that such management intervention can be used, at least, for the short-term restoration of ecological water quality and prevention of noxious cyanobacterial bloom formation. The negative result of biomanipulation in one pond seems to be related to the pollution by sewage water. Guest editors: B. Oertli, R. Cereghino, A. Hull & R. Miracle Pond Conservation: From Science to Practice. 3rd Conference of the European Pond Conservation Network, Valencia, Spain, 14–16 May 2008     

Understanding and addressing waste of food in the Kingdom of Saudi Arabia

IntroductionMultiple estimates suggest the Kingdom of Saudi Arabia (KSA) may have one of the highest rates of wasted food globally. The KSA has limited arable lands and scarce water and thus relies on extensive imports and food subsidies to meet food demand. Accordingly, waste and loss of food are a significant concern for food security.Materials and methodsA narrative literature review was performed to identify the available information relevant to characterizing the context, magnitude of food wasted in the KSA, key contributing factors, and existing interventions and recommendations.ResultsEstimates of annual per capita waste of food ranged from 165 kg to 511 kg. Given the country's relatively limited agricultural production, the consumer and retail levels are primary targets for intervention. Key contributors to waste include culture, food valuation, policy and industry factors, and awareness and concern. The country is at an early stage of developing responses. We build upon existing approaches and recommendations, with particular emphasis on the potential role of agricultural extension staff in addressing the issue, and highlight research needs.ConclusionsGiven the potentially exceptional levels of wasted food in the KSA and the extensive evidence gaps, there is a great need for further research and action. Our review and synthesis presents numerous opportunities to advance innovative waste reduction approaches in the country, with particular relevance for other parts of the Middle East and other areas early in their efforts to address waste of food.     

Biofilm development and the dynamics of preferential flow paths in porous media

A two-dimensional pore-scale numerical model was developed to evaluate the dynamics of preferential flow paths in porous media caused by bioclogging. The liquid flow and solute transport through the pore network were coupled with a biofilm model including biomass attachment, growth, decay, lysis, and detachment. Blocking of all but one flow path was obtained under constant liquid inlet flow rate and biomass detachment caused by shear forces only. The stable flow path formed when biofilm detachment balances growth, even with biomass weakened by decay. However, shear forces combined with biomass lysis upon starvation could produce an intermittently shifting location of flow channels. Dynamic flow pathways may also occur when combined liquid shear and pressure forces act on the biofilm. In spite of repeated clogging and unclogging of interconnected pore spaces, the average permeability reached a quasi-constant value. Oscillations in the medium permeability were more pronounced for weaker biofilms.     

农业生态经济系统生产力评价指标体系研究

本文着眼于如何把生态经济理论应用于生产实践,探讨了农业生态经济系统生产力评价指标体系的建立原则和方法,设计出一套包括6项综合指标在内的评价指标体系,并根据对北京留民营、窦店2个典型系统的计算,初步确定出京郊农业生态经济系统的参照指标,从而进一步对京郊渠头农场的系统生产力水平进行了评估分析,取得了比较满意的结果。     

An expert-based landscape permeability model for assessing the impact of agricultural management on amphibian migration

The persistence of pond-breeding amphibian populations is influenced on different spatial scales ranging from the individual breeding pond to surrounding habitat patches to landscape clusters of breeding pond populations. The connectivity among breeding ponds as well as the availability of suitable terrestrial habitats surrounding the ponds plays a major role in long-term viability of amphibian species. Besides road traffic and urban structures agricultural land activity can disrupt landscape connectivity through the use of pesticides, fertilizers and physical activity such as tillage. We developed an expert-based model to assess the impact of agricultural management measures on the migration area and terrestrial habitat availability for seven amphibian species. The model is based on a Habitat Suitability Index to identify suitable terrestrial habitats and includes a landscape permeability approach. Size of migration areas, connectivity of breeding ponds and number of reachable terrestrial habitats were modeled considering species-specific migration ranges and habitat preferences. We consider how pesticides application might lead to fragmentation and isolation of amphibian breeding pond populations. Therefore the potential disrupting impact of pesticides was simulated by inflating landscape resistance to medium and high migration cost. One amphibian species showed a decrease of migration area by 48.3% and a decrease of reachable terrestrial habitats by 41.5% at high migration costs. Three additional species showed a decrease of their migration areas between 31.5 and 35.7%. At increased migration cost, some of the investigated populations were isolated at breeding pond level or restricted to pond clusters. Our model could be used to prioritize conservation efforts for pond-breeding amphibians with adequate consideration of agricultural land use and its impact on amphibian migration.     

Thermodynamic rarity of electrical and electronic waste: Assessment and policy implications for critical materials

The strategic relevance of extracting raw materials from waste from electrical and electronic equipment (WEEE) in the EU is increasing due to value chain risks caused by geopolitical instability, accessibility of specific minerals, and decreasing reserves due to growing extraction rates. This article examines the quantities of so-called critical raw materials (CRMs) originating within WEEE streams from a depletion perspective. Presently, current recycling targets are based solely on mass collection and recycling rates. We examine the potential limitations of this approach using an exergy-based indicator named thermodynamic rarity. This indicator represents the exergy costs needed for producing materials from the bare rock to market. The case of Italy is used to explore the application of the indicator at the macro (national) and micro (company) level for the product categories “small electronics” and “screens and monitors.” Our estimations show significant differences between the mass and rarity of materials within Italian WEEE streams. While iron accounts for more than 70% of the weight of the product categories analyzed, it accounts for less than 15% of the rarity. Similarly, several CRMs with a small mass have a higher rarity value, for example, tungsten with less than 0.1% of the mass and over 6% of the rarity. The policy context is reflected upon, where it is argued that thermodynamic rarity can provide novel insights to support end-of-life WEEE decision-making processes, for example, target development and recycling standards setting to help prioritize material monitoring and recovery options.     

A Quadrupole Dalton-based multi-attribute method for product characterization,process development,and quality control of therapeutic proteins

During manufacturing and storage process, therapeutic proteins are subject to various post-translational modifications (PTMs), such as isomerization, deamidation, oxidation, disulfide bond modifications and glycosylation. Certain PTMs may affect bioactivity, stability or pharmacokinetics and pharmacodynamics profile and are therefore classified as potential critical quality attributes (pCQAs). Identifying, monitoring and controlling these PTMs are usually key elements of the Quality by Design (QbD) approach. Traditionally, multiple analytical methods are utilized for these purposes, which is time consuming and costly. In recent years, multi-attribute monitoring methods have been developed in the biopharmaceutical industry. However, these methods combine high-end mass spectrometry with complicated data analysis software, which could pose difficulty when implementing in a quality control (QC) environment. Here we report a multi-attribute method (MAM) using a Quadrupole Dalton (QDa) mass detector to selectively monitor and quantitate PTMs in a therapeutic monoclonal antibody. The result output from the QDa-based MAM is straightforward and automatic. Evaluation results indicate this method provides comparable results to the traditional assays. To ensure future application in the QC environment, this method was qualified according to the International Conference on Harmonization (ICH) guideline and applied in the characterization of drug substance and stability samples. The QDa-based MAM is shown to be an extremely useful tool for product and process characterization studies that facilitates facile understanding of process impact on multiple quality attributes, while being QC friendly and cost-effective.     

The kinetics of nicotine degradation,enzyme activities and genotoxic potential in the characterization of tobacco waste composting

This study aimed to determine nicotine biodegradation and the genotoxic potential of nicotine and its degradation products during the process of tobacco waste composting. Composting was carried out using two methods, i.e. the addition of 20% (bioreactor A) or 40% tobacco wastes to sewage sludge (bioreactor B) and control – sewage sludge (bioreactor C). Wheat straw was used as a structure-forming material. As a result of composting the contents of C and N in the bioreactors changed, the C:N ratio in bioreactor A changed from 22.8 to 13.00, and that in bioreactor B changed from 23.5 to 12.00. After composting, the biodegradation rate of nicotine was 78% in bioreactor A and 80% in bioreactor B, respectively. Using the Ames test it was shown that the composts produced did not exhibit mutagenicity.     

Optimization and effect of dairy industrial waste as media components in the production of hyaluronic acid by Streptococcus thermophilus

Hyaluronic acid (HA) production using a dairy industrial waste is a more cost-efficient strategy than using an expensive synthetic medium. In this study, we investigated the production of HA using Streptococcus thermophilus under shake flask conditions using dairy industrial waste as nutritional supplements, namely whey permeate (WP) and whey protein hydrolysate (WPH). Preliminary screening using Plackett–Burman design exhibited WP, WPH, initial pH, and inoculum size as significant factors influencing HA titer. Response surface methodology design of four factors was formulated at three levels for enhanced production of HA. Shake flask HA fermentation by S. thermophilus was performed under global optimized process conditions and the optimal HA titer (342.93?mg?L^?1) corroborates with Box–Behnken design prediction. The molecular weight of HA was elucidated as 9.22–9.46?kDa. The ultralow-molecular weight HA reported in this study has a potential role in drug and gene delivery applications.