Application of Box-Behnken Design for Optimization of Different Pretreatment Conditions for Cellulase Production

Effects of dilute acid and acid steam pretreatments were inspected for cellulose production of Eucalyptus leaves through Box-Behenken design,a three variable factors for response surface methodology by Bacillus subtilus K~(-1)8.Maximum cellulose production performed in 250 mL erlenmeyer flask with submerged fermentation attained at 50℃,p H 5,140 r·min~(-1) for 24 h.Results showed the efficient cellulose production from acid steam pretreatment(being autoclaved at 15 Psi for 15 min)than acid pretreatment.The optimum condition for maximum carboxymethyl cellulas(CMCase)was 1.811 IU·mL~(-1)·min~(-1)(0.8%acid conc.,10 g biomass loading,6 h reaction time)and filter paper activity(FPase)was 2.255 IU·mL~(-1)·min~(-1)(1%acid conc.,10 g biomass loading,8 h reaction time).Whereas,the acid steam maximum CMCase activity recorded was 2.585 IU·mL~(-1)·min~(-1)(0.8%acid conc.,15 g substrate loading and 8 h reaction time)and the highest FPase activity was 2.055 IU·mL~(-1)·min~(-1)(0.8%conc.,10 g biomass,6 h reaction time then autoclaved).Results revealed that acid pretreated Eucalyptus leaves were better lignocellulosic biomass for cellulose production by submerged fermentation.     

Effect of Different Indole-3-Buteric Acid (IBA) Concentrations and Cutting Types on Plane Trees (Platanus orientalis L.)

Effects of different Indole-3-Buteric Acid (IBA) concentrations (0, 1000, 1500 and 2500 ppm) and cutting types (soft wood, semi hard and hard wood) of plane tree were investigated with Randomized Complete Block Design (RCBD) at the Agricultural research station, Charsadda. The maximum survival percentage, plant height (cm), root length (cm), numbers of roots and root weight per cutting were significantly higher in hard wood cuttings. IBA concentration had no speculative effect on plane tree cuttings. Thus, hard wood cutting was the best choice for plan tree propagation.     

Sensing and control system for spot-application of granular fertilizer in wild blueberry field

An automated sensing and control system (hardware and software) was developed for real-time spot-application of granular fertilizer in mowed wild blueberry fields. The custom hardware system was incorporated into a commercial pneumatic granular fertilizer spreader. Custom software for the sensing and control system was developed by combining color co-occurrence matrix based texture analysis and g-ratio algorithms in C++ to acquire and process images in real-time to differentiate mowed wild blueberry plants from bare spots and weeds. The performance accuracy of the spot-applicable fertilizer spreader was evaluated both in laboratory simulation and real-time field tests. Simulation results reported that the accuracy of the developed system was 94.9 %. Real-time field tests reported that the system produced acceptable results at ground speeds of 1.6 and 3.2 km h^?1 for the spot-application of fertilizer at target areas (in plant areas only) within the field. Results also indicated that the ground speed of 4.8 km h^?1 was unacceptable, which could be due to blurred images at high speed and surface unevenness of the wild blueberry field. Spot-application of fertilizer using the modified fertilizer spreader could save fertilizer for the wild blueberry producers.     

Identifying glyphosate-tolerant maize by soaking seeds in glyphosate solution

The identification of glyphosate-tolerant maize genotypes by field spraying with glyphosate is time-consuming, costly and requires treatment of a large area. We report a potentially better technique of seed-soaking to identify glyphosate-tolerant maize genotypes. The effects of soaking maize seeds in glyphosate solution under controlled conditions were studied on seed germination rate, seedling morphological indices, seedling growth and leaf chlorophyll content. These responses were compared among a glyphosate-tolerant transgenic maize cultivar CC-2, glyphosate-susceptible inbred line Zheng 58 (the recurrent parent of CC-2) and hybrid cultivar Zhengdan 1002. The results showed that the germination rate, seedling morphological indices and leaf chlorophyll content of glyphosate-tolerant CC-2 seeds did not change significantly among five different concentrations of glyphosate treatment (0 to 2%). In contrast, germination rates, seedling morphological indices and leaf chlorophyll contents of Zheng 58 and Zhengdan 1002 seeds were significantly negatively affected by exposure to increasing concentrations of glyphosate. The glyphosate-tolerant inbred line CC-2 displayed a strong tolerance to glyphosate after soaking in 0.1 to 2.0% glyphosate solutions, while both the inbred line Zheng 58 and hybrid Zhengdan 1002 were susceptible to glyphosate. The accuracy of the glyphosate-soaking method for screening glyphosate-tolerant maize was confirmed using a field spraying trial.     

Effect of carbonic anhydrase-containing endophytic bacteria on growth and physiological attributes of wheat under water-deficit conditions

Drought is one of the major limitations to agricultural productivity, suppressing plant growth and yield of food crops throughout the world particularly in arid and semiarid regions. Drought-tolerant carbonic anhydrase (CA; EC 4.2.1.1)-containing endophytic bacteria may improve plant growth under stressed conditions. In the present study, effect of drought-tolerant CA-containing endophytic bacteria on growth and physiology of wheat under water-deficit conditions was studied. One hundred and fifty isolates were isolated from wheat plants and screened for their ability to tolerate polyethylene glycol (PEG) 6000-induced water-deficit stress (?0.31 to ?3.20 MPa). Fifty isolates exhibiting intrinsic ability to tolerate stress were further screened for CA activity. Ten drought-tolerant isolates with higher CA activity were evaluated for improving wheat growth under water-deficit conditions (?0.04, ?1.09, ?1.23 MPa). Results showed that PEG-mediated water-deficit stress significantly reduced growth of wheat. However, inoculation with isolates WR2, WS11 and WL19 significantly enhanced seedling growth by improving maximum root length, shoot length, root and shoot dry weight under non-stressed as well as stressed conditions. These isolates were identified by 16S rRNA as Bacillus marisflavi (WR2) Bacillus thuringiensis (WS11) and Bacillus subtilis (WL19). Isolate WL19 also improved chlorophyll content, photosynthetic rate, CA activity and relative water content compared to uninoculated control plants. Overall, our findings suggest that endophytic bacterial isolates WR2, WS11 and WL19 with CA activity can enhance photosynthesis and biomass of wheat seedlings under water-deficit conditions.

Abbreviations: CA: Carbonic anhydrase; PEG: Polyethylene glycol; CO₂: Carbon dioxide; HCO^3–: Bicarbonate; TSA: Tryptic Soy Agar; LB: Luria Bertani; A: CO₂ assimilation rate; E: Transpiration rate; g_s: Stomatal conductance; C_i: Substomatal CO₂ concentration; RWC: Relative water content; EL: Electrolyte leakage     

Development of Maghemite Glass Fibre Nanocomposite for Adsorptive Removal of Methylene Blue

Maghemite glass fibre nanocomposite with excellent magnetic and adsorption properties was successfully developed from nontoxic and eco-friendly reagents by thermal decomposition approach. The developed nanocomposite was utilized in adsorption of methylene blue which follows Freundlich adsorption isotherm. The excellent value of adsorption capacity (51.31 mg g^-1) as compared to other adsorbents recommends its potential role for adsorption phenomenon in multiple applications. The developed nanocomposite can be recycled and reused easily. Surface and other functional characteristics of developed nanocomposite were determined through scanning electron microscopy, X-ray diffraction, raman spectroscopy, energy dispersive X-ray spectroscopy and vibrating sample magnetometer. The obtained results revealed that maghemite glass nanocomposite is a potential tool that can be utilized in waste water treatments.     

Strategic use of water: a step toward cadmium-free basmati rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.)

Sewage contains several trace elements of environmental concern, and cadmium (Cd) is one of the most mobile elements in soil–plant system that can pose drastic effects on plants and human health due to its long persistence and non-biodegradability nature in environment. It is necessary to prevent its entry into food chain for better food quality and human health. Present study was designed to evaluate the effectiveness of different water management practices, viz. W₁: flooding throughout the growing season, W₂: flooding after 4 days of disappearance of standing water (DAD), W3: flooding till heading and after that flooding of soil after 4 days of DAD, W₄: Aerobic condition throughout growing season (flooding after 8 days) for reducing Cd concentration in rice grain grown under varying levels of Cd (0, 20, 40 mg kg^?1) spiked soil. Results revealed that grain yield declined with increasing Cd levels but maximum plant height (89.3 cm), straw yield (16.9 g) and grain yield (22.5 g pot^?1) was observed where pots were flooded till heading and thereafter flooding. Cadmium concentration increased with increasing concentration of Cd in soil. Further, it is added that the lowest Cd concentration in shoot, grain and husk and translocation factor were observed under W₃ when the soil was spiked with 40 mg kg^?1. In crux, continuous flooding till heading and thereafter flooding after 4 DAD can significantly decrease the grain Cd concentration without compromise on yield.     

Determination of Residual and Cumulative Boron Requirements for Cotton and Wheat Crops Grown Under Calcareous Soil Conditions

A two-year field experiment was conducted to elucidate the residual and cumulative boron (B) requirements for cotton and wheat crops. For the first time, cotton was sown in randomized complete blocks those received 0.0, 1.0, 1.5, 2.0, 2.5 and 3.0 kg B ha^?1 as borax (Na₂B₄O₇.10H₂0). Later, each plot was divided into two subplots for successive wheat and cotton crops and half of the pots received B at similar rates. Our results revealed that direct application of B at the rate of 2 and 2.5 kg ha^?1 produced optimum cotton yield during 2005. The same rates of B were consistent in residual plots but not in cumulative plots for both of the crops in successive years. It was thus concluded that soil applied B at the rate of 2.0 and 2.5 kg ha^?1 had significant residual effects on cotton and wheat yields.