Revista de bioprocesamiento y biotecnologías

We have studied the slow dynamics of isolated complexes of chlorophyll-containing membrane proteins of photosynthetic Reaction Centers (RCs) of Rb. sphaeroides R-26 induced by light fluxes. The analysis of a variation of the absorption of a solution of RCs in the frame of the three-level model is carried out. The equation defining the ratio of the populations of the electron levels of the primary and secondary quinones is deduced. The solution of this equation has non-Boltzmann character even in the stationary case and depends on the exciting light intensity. A model of the dynamics of levels of RC which accounts the presence of polarization processes in the vicinity of the secondary quinone acceptor (QB) is proposed. It is assumed that all RCs have the same structure but can be in different states, whose characteristics depend on both the time interval having passed after the absorption of a light quantum and the local viscosity and elasticity of the environment of QB. The presence of deformational properties of the environment of QB yields the possibility for a configuration of RC to be changed, which agrees with the experimental data.

Recognizing the effects of dwindling natural feed stocks of energy and synthetic materials, their high costs along with the resulting effects by their use on the environment and emission of greenhouse gases into the environment, greater thrust has been placed on the use of eco friendly and energy saving biomaterials and processes. These efforts have led to a new approach to the development of new materials, products and processes along with the implementation of sustainable manufacturing strategies. Such strategies would help in optimizing the total material cycle from virgin material up to finished products. These also include utilization of wastes generated whereby ultimate disposal of wastes is achieved. Such efforts will have great impact on the world economy and improvement of quality of life. Considering the above and the abundantly available, but underutilized biomaterial resources, several attempts have been made all over the world giving excellent opportunities for scientists to discover methods for their better utilization. This paper discusses some of the recent research efforts made, including the author’s involvement in these, to develop environmentally friendly and sustainable ‘green’ composites based on plant fibers with details on their processing matrix-reinforcement combinations, morphology and properties. These materials have found use in automotive, construction, packaging, medical and other sectors.

The rheological parameters: flow behaviour index n, flow consistency index K and effective viscosity ηe were estimated for the entomoparasitic nematodes Heterorhabditis bacteriophora liquid broth at different culture maturation times. The nematode or nematodes were cultivated during 20 days in a bioreactor, and the growth media inside the bioreactor was enriched with protein and fat sources. Rheological parameters for the heterogeneous suspension were estimated with mixer principles employing a helical ribbon agitator fixed to a rheometer. As the culture matured, n decreased from 0.8 to 0.2 (-) and K increased up to 1200 mPa•sn; ηe showed a non-Newtonian (n<1) behaviour, ηe reached peak values of 0.32 Pa•s for a rotational speed of 0.5 revolutions per second (rps) and 0.048 Pa•s for 2.5 rps. Rheological properties reported here could be more reliable as compared to those reported for non-homogeneous liquid fermentations where estimations were performed with conventional geometries (i.e. concentric cylinders) which are appropriate for homogeneous systems but not for non-homogeneous ones.

With the progress of nanotechnology and increase in demand, several silica processing industries have started producing silica nanoparticles. As a result, the search for new sources capable of producing this material has been attracting the interest of many researchers. With this background, a study was carried out to obtain silica nano particles from the Equisetum arvenses, a plant that possesses one of the highest amounts of silicon. This paper presents the preparation of nano silica particles with different combinations of acid washing and calcination at varying temperatures between 773 K and 873 K. The nanoparticles produced were characterized for nitrogen adsorption, morphology using transmission electron microscope and structural analysis by X-ray fluorescence and diffraction. It was found that nanoparticles produced by two cycles of acid washing and calcination at 773 K gave the best results, producing a material with white color, the highest specific surface area of about 330 m²/g with diameter of about 8 nm, and 93.5% of amorphous silica. The nanoparticles obtained can be potential industrial raw material for many applications.

Modern sustainable agricultural practices prefer to use biological agents for plant growth promotion, biocontrol and bioremediation as these are cost effective and eco-friendly. Our present study aims to investigate the effects of direct inoculation of selected consortia on plants to study its effects on supporting plant growth in the presence of root pathogen Sclerotium rolfsii and organophosphate pesticides Malathion (ML) and Methyl Parathion (MP). Candidate Plant Growth Promoting Microbial (PGPM) isolates chosen for the study are two bacterial isolates (PGPM2 a diazotrophic bacterium, PGPM9 a fluorescent Pseudomonad) and one fungal species (T103 a biocontrol fungus), originating from native agricultural fields of western U.P., India. Host plants inoculated with individual species showed a distributed growth enhancement pattern i.e., while isolate T103 improved root biomass, isolate PGPM9 enriched photosynthetic pigment content and isolate PGPM2 expanded root and shoot lengths. It appeared as though individual isolates showed a preference to enhance certain parameters over the other rather than exhibiting a uniform increment in all growth parameters. This preference to specific growth parameter over the other waned off in consortium studies where Sorghum bicolor inoculated with the consortium registered almost 2-fold increase in all parameters viz., root length, shoot length and overall biomass (root, shoot and total biomass) along with 23% rise in total chlorophyll content as compared to un-inoculated control. Selected consortia combination was able to provide better growth promotion in presence of pathogen Sclerotium rolfsii registering 58% increase in total biomass content while individual inoculation of biocontrol fungus T103 showed only 36% improvement. Selected consortia were also effective in plant growth promotion in presence of organophosphate pesticides ML and MP. More than two fold amplification was registered in all roots and shoot growth parameters studied when consortia was provided with ML and 28% increase was recorded when MP treatment was countered with consortia inoculation. All these results affirms our hypothesis that synergistic action of carefully selected PGPMs can escalate the benefits of plant growth promotion even in presence of pathogen and pesticide, hence this consortia may be a valuable option for sustained plant growth in modern agriculture systems.

The 1,4-β-D-glucan glucohydrolase gene (Ggh) which was isolated from Paenibacillus sp. strain HPL-001 (KCTC11365BP) has been cloned and expressed in Escherichia coli, and efficiently purified using affinity column chromatography. Recombinant 1,4-β-Dglucan glucohydrolase (719aa, NCBI accession number KJ573391) was highly active at 40°C in pH 6.0 without significant changes to most salts tested, and exhibited Km 0.893 mg/mL Vmax 33.33 U/mg on pNPG, respectively. All soluble cellooligomers (e.g., cellobiose, cellotriose, cellotetraose, cellopentaose, and cellohexaose) had been virtually hydrolyzed to glucose by this enzyme. When compared with the commercialized-enzymes, the hydrolytic pattern to all substrates was almost same to the Celluclast 1.5L (Novozyme) with about 1/3 strength, however hydrolytic pattern of Glucosidase (Lucigen) and Almonds (Sigma) was significantly decreased with substrates increasing number of glucose polymer from cellotriose to cellohexaose. About 90% of the initial enzyme activity was maintained even after 10 consecutive recycle by the 11-carbon bridge and aldehyde-functionalized MCF-immobilization. 3-D structure of this enzyme has the ligand of cellobiose and cellulose binding in the center of niche according to the sequence information.

Lipases are one of the most promising enzymes in the chemical and biopharmaceutical industries. Numerous applications have been reported including fine chemistry, detergents formulation and biodiesel synthesis. Lipases are commonly produced by a wide variety of yeasts and filamentous fungi in submerged fermentation or solid-state fermentation. Filamentous fungi and yeasts usually behave more efficiently in solid-state fermentation and show greater productivities when compared to submerged fermentation. Although filamentous fungi adequately growth in solid-state fermentation, there are some limitations for cultivating them by this process. Here, a review is made about lipase production in solid-state fermentation. This includes the analysis of solid-state fermentation as a promising technology, characterization of growth media and ambient factors such as moisture, pH and temperature.

Rat and mouse have become important animal models to study various human diseases such as cancer. Here, we use eggplant peel ethanolic extract to visualise chromosome banding. This extract is easy to prepare, a novel, available alternative. The colour of this extract is bright dark green colour. This stain gave us good result for show the chromosomes banding, we used Thin Layer Chromatography (TLC) examination, Infrared (IR) spectroscopy and the spectrum ultraviolet UV to investigate about the compound and functional groups in this extract. Use of this extract represents a new method for chromosome banding and a viable alternative to existing chromosome staining methods.

Chicken manure has high solid and high ammonia content which dictates the dilution of feed material with huge amount of freshwater in order to minimize ammonia toxicity, if it is to be digested alone. In this study, a novel approach is presented to significantly minimize fresh water need for biogas application and to eliminate the construction of costly digestate storage tanks. For this purpose, membrane process which allows recycling of digestate after ammonia removal was integrated to the conventional biogas system. Therefore, the selection of proper membranes for the removal of ammonia from digestate was carried out by testing six different types of Nano Filtration (NF) membranes (NF270, NF245, NF200, NF90, NF-NF, NP010) and three different types of Reverse Osmosis (RO) membranes (BW30, SW30, X20) in cross flow microfiltration experiments. The performance of the membranes was tested by monitoring parameters such as pH, conductivity, COD, TN, NO2-N, NO3-N, TP in the permeate under various operating conditions. NF90 (83%) and X20 (92%) type membranes were found to be most effective for the removal of TN from the digestate. Moreover, COD (Chemical Oxygen Demand) removal efficiency reached up to 99% for both NF90 and X20 membrane.

The genus Fusarium is comprises of different species which are furtherer divided into small groups called formae speciales according to their host specificity. It is remarkable that while an isolate belonging to particular formae speciales is considered highly pathogenic in a certain plant species, the many other isolates belonging to the same formae speciales may have no harm effect or even a beneficial relation to the same host plant. Traditionally, bioassays conducted under green house conditions were used to distinguish pathogenic and non-pathogenic isolates. However, such these techniques have some limitations due to the time consuming and the inconsistency of obtained results. In contrary, molecular identification techniques are candidate to play an important role in the characterization process of Fusarium isolates as well as with many other organisms. Recently, the ability of a Fusarium isolate to infect particular plant species was found to be dependent on specific genes encoding host determining ‘virulence factors’ that distinguish virulent from avirulent strains. More recently, eight fungal proteins were identified from xylem sap of infected plants, encompassing the small secreted proteins called Six1, Six2, Six3, Six4, Six5, Six6, Six7 and SIX 8. In the present study, the linkage between virulence potential of fifteen pathogenic isolates in addition to one non-pathogenic isolate, Fo162 , of Fusarium oxysporum and the presence of secreted in xylem effector genes (SIX) was determined. The results showed that the tested isolates were varied regarding to their pathogenicity potential toward tomato plants under greenhouse conditions. On the other hand, the amplicons of SIX1, SIX5 and SIX 7 were detected with most hyper virulent isolates while no amplicons for any tested SIX genes were observed with the non-pathogenic isolate (Fo162) as well as with the most hypo virulent isolates. These results, suggested that SIX1, SIX5 and SIX6 may play a distinct role in virulence potential of these Fusarium oxysporum isolates toward tomato plants under Egyptian conditions.