Native Isolates Research Articles

Efficacy of Purpureocillium lilacinum AUMC 10149 as biocontrol agent against root-knot nematode Meloidogyne incognita infecting tomato plant.

Root-knot nematode Meloidogyne incognita is among the biotic factors which has greatly affected both the yield and the quality of the tomato crop. The egg parasitic nematode, Purpureocillium lilacinum (Pl) is considered as one of the most promising agents in controlling and overcoming this plant pathogen. The nematicidal effect of the native isolate Pl AUMC 10149 on second stage juvenile's survival and egg hatching of M. incognita at different times of exposure was tested in vitro. The obtained data showed that Pl gave a maximum percentage of J2 mortality (97.6%) and egg hatching inhibition (79.8%) after 72 hours of exposure. The potentiality of Pl as well as Bio-Nematon to control M. incognita infecting tomato was conducted using different times of application in vivo. Nine treatments with five replicates were used for such bioagents compared with the nematicide Oxamyl. Each seedling was inoculated with 1000 J2s of nematode/pot and 10 mL of Pl (1x1010 CFU/mL) or Bio-Nematon spore suspension (1x108 CFU/mL) 10mL/pot. The results indicated that the most effective treatments in reducing nematode population, number of galls and egg masses of M. incognita in plant roots was performed with treatment by Pl pre-planting and post-infection with Pl (Rf 1.9) giving a significant enhancement in plant length (64.9%), fresh weight (72.52%) and shoot dry weight (163.41%) without negatively impacting environment. Therefore, the present study confirmed that using P. lilacinum AUMC 10149 can be used as a practical supplement to environmentally friendly disease management of root-knot nematodes in Egypt.

<i>In vitro</i> evaluation of microencapsulated <i>Bacillus thuringiensis</i> exposed to different temperatures against <i>Helicoverpa armigera</i> (Hubner)

The experiment was conducted to prepare and evaluate microencapsulation of lyophilized Spore Crystal Aggregate (SCA) of native Bacillus thuringiensis isolate BGC-1 and standard isolate HD-1 against second instar larvae of Helicoverpa armigera at the Department of Agricultural Entomology, Bheemarayanagudi. The zetasizer analyzer results revealed that the microcapsule diameter ranged from 3.2 to 8.3 µm. Median lethal concentrations of the BGC-1 and Bt-HD1 were 0.66 g/l and 0.50 g/l, respectively. UV protectants viz., melanin and (PABA) para-amino benzoic acid were evaluated by exposing microencapsulated Bacillus thuringiensis to temperature regimes of 25°C, 30°C, 35°C, 40°C and 45°C in the B.O.D at different intervals of time. Among four microencapsulated formulations, BGC-1 with melanin recorded the highest mortality of 95 % at zero h exposure. As time increased, the mortality decreased and HD-1 was on par with BGC-1. HD-1 melanin showed significantly higher mortality of 62.50 to 92.50 % followed by BGC-1 (melanin) which ranged from 70 to 90 %. Even though formulations were exposed to different temperatures, because of encapsulation, potential to cause insect mortality was retained.

Effect of Entomopathogenic Fungi to Eggs and Nymphs Survival of Halyomorpha halys (Hemiptera: Pentatomidae) Under Laboratory Conditions.

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is becoming a major pest of Greece's agricultural production, including tree fruit. Until now, the control of this pest has been based on conventional methods, with the application of chemical insecticides being the primary option. However, the wide distribution of H. halys, in combination with the large area of tree fruit production in Greece, raise the need for alternative control methods. In this study, we investigated the possibility of implementing microbial control agents for managing H. halys. Eggs and nymphs of H. halys were treated with 15 native entomopathogenic fungal isolates and their virulence was evaluated in the laboratory. After treatment, egg hatching time was recorded for 7days and ranged from 4.5 to 7.0days. Nymphal survival was recorded daily for 7days following application and ranged from 2.1 to 6.6days for second instar nymphs and 3.7 to 6.8days for fourth instar ones. Beauveria varroae isolate displayed the highest toxicity to all H. halys stages that were tested and could be considered a promising biocontrol agent of this insect. Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.οκ.

Systems metabolic engineering of the primary and secondary metabolism of Streptomyces albidoflavus enhances production of the reverse antibiotic nybomycin against multi-resistant Staphylococcus aureus

Nybomycin is an antibiotic compound with proven activity against multi-resistant Staphylococcus aureus, making it an interesting candidate for combating these globally threatening pathogens. For exploring its potential, sufficient amounts of nybomycin and its derivatives must be synthetized to fully study its effectiveness, safety profile, and clinical applications. As native isolates only accumulate low amounts of the compound, superior producers are needed. The heterologous cell factory S. albidoflavus 4N24, previously derived from the cluster-free chassis S. albidoflavus Del14, produced 860 μg L−1 of nybomycin, mainly in the stationary phase. A first round of strain development modulated expression of genes involved in supply of nybomycin precursors under control of the common Perm* promoter in 4N24, but without any effect. Subsequent studies with mCherry reporter strains revealed that Perm* failed to drive expression during the product synthesis phase but that use of two synthetic promoters (PkasOP* and P41) enabled strong constitutive expression during the entire process. Using PkasOP*, several rounds of metabolic engineering successively streamlined expression of genes involved in the pentose phosphate pathway, the shikimic acid pathway, supply of CoA esters, and nybomycin biosynthesis and export, which more than doubled the nybomycin titer to 1.7 mg L−1 in the sixth-generation strain NYB-6B. In addition, we identified the minimal set of nyb genes needed to synthetize the molecule using single-gene-deletion strains. Subsequently, deletion of the regulator nybW enabled nybomycin production to begin during the growth phase, further boosting the titer and productivity. Based on RNA sequencing along the created strain genealogy, we discovered that the nyb gene cluster was unfavorably downregulated in all advanced producers. This inspired removal of a part and the entire set of the four regulatory genes at the 3′-end nyb of the cluster. The corresponding mutants NYB-8 and NYB-9 exhibited marked further improvement in production, and the deregulated cluster was combined with all beneficial targets from primary metabolism. The best strain, S. albidoflavus NYB-11, accumulated up to 12 mg L−1 nybomycin, fifteenfold more than the basic strain. The absence of native gene clusters in the host and use of a lean minimal medium contributed to a selective production process, providing an important next step toward further development of nybomycin.

The Eucalyptus snout beetle in Colombia: Selection and evaluation of entomopathogenic fungi as bioinsecticides against Gonipterus platensis

The Eucalyptus snout beetles, which belong to the Gonipterus scutellatus species complex, cause heavy damage to Eucalyptus spp. worldwide. The species was reported in Antioquia, Colombia for the first time in 2016, threatening more than 115,000 ha of planted Eucalyptus spp. Elsewhere, its damage has been controlled using Anaphes spp. as classical biological control, but Anaphes spp. are not available in Colombia, where there are no documented control methods for this species to date. We identified the Gonipterus species using molecular methods and isolated entomopathogenic fungi from naturally infected beetles collected from the current distribution area in Colombia. We characterised the fungal isolates, selecting the best to develop a biological control agent. We considered insecticidal activity, UV-B radiation tolerance, yield, germination, and enzyme activity of conidia in making our selection. We confirmed the presence of G. platensis in Colombia, with adults naturally infected by Beauveria spp. and Metarhizium spp. From the isolated native fungi, M. brunneum (CA-3), M. robertsii (RI-1), B. bassiana (CA-1) and (CA-2), B. pseudobassiana (SP-1) were identified. We found remarkable differences in response to different variables between the selected isolates and SP-1 and CA-3 were the most virulent. The SP-1 isolate stood out from the rest for being the most tolerant to UV-B radiation, alkaline media, and low temperatures, germinating faster and producing elevated levels of lipases, chitinases, and proteases. The identified promising native fungus isolate, naturally occurring on field individuals, could be used to develop a biopesticide for controlling G. platensis in Eucalyptus spp. plantations in Colombia.

Efficacy of native Bacillus isolates against different larval instars of fall armyworm, Spodoptera frugiperda alone and in combination

BackgroundFall armyworm (FAW) Spodoptera frugiperda (J.E. Smith) Lepidoptera: Noctuidae is an invasive polyphagous pest that causes severe damage to several agricultural crops. The use of pesticides is limited because of their mode of feeding and resistant development. Hence, the present work aimed to determine the pathogenicity of entomopathogenic bacteria (Bacillus spp.) against FAW in terms of mortality and growth inhibition. In this study, initially 49 native Bacillus isolates, isolated from diverse habitats in India, along with five reference strains, were screened for their efficacy against neonates of S. frugiperda under controlled laboratory conditions, followed by virulence and combinatorial bioassays.ResultsFive native Bacillus isolates (VKK1, VKK5, S16C2, S25C1, and SOIL 20) showed mortality in the range of 35.49–65.52% against neonates of S. frugiperda at single concentration (1000 μg g−1 of diet). These five isolates, along with one reference strain Btk-HD1 (Bacillus thuringiensis serovar kurstaki strain HD1), were further tested to find the median lethal concentration (LC50) for neonates of S. frugiperda. Among these, native Bt strain VKK5 showed the lowest LC50 (718.40 µg/g of diet) and HD1 showed the highest LC50 (3352 µg/g of diet). Combinatorial bioassay against neonate and third instar larvae showed that the combination of VKK5 and VKK1 had an additive effect. Moreover, growth inhibition was also recorded.ConclusionThe combination of Bt strains leads to an enhancement of pathogenicity toward FAW larvae at the initial stage of development, and in later stages, it affects their growth and development. Thus, biocontrol of FAW by entomopathogenic bacteria (Bt) can play a vital role in the effective management of FAW.

Evaluation of the potential of native Trichoderma spp. against root-rot diseases of soybean

Three native Trichoderma isolates, Trichoderma koningii (OP050066), Trichoderma harzianum (OP050067), and Trichoderma viride (OP050068) selected of fourteen different native Trichoderma spp. isolated from rhizosphere of healthy soybean fields in Al-Baha region (Baljurashi Province) Saudi Arabia, were evaluated in-Vitro and under greenhouse conditions against the soil-borne fungi Rhizoctonia solani (OQ345525), Fusarium solani (OQ345527) and Fusarium oxysporum (OQ345526) isolated from soybean plants in the same region. The three tested Trichoderma isolates significantly inhibiting the mycelial growth of the three selected pathogens R. solani, F. solani and F. oxysporum in-Vitro and reduced the percentages of pre- and post-emergence damping-off caused by the three tested pathogenic fungi with significant increase of the survived soybean plants under greenhouse conditions. Furthermore, activities of peroxidase, polyphenoloxidase and chitinase oxidative enzymes of the treated plants were increased over the untreated control. The obtained results revealed the possibility of using that native Trichoderma isolate of soybean root disease management.

Studies on Symptomatology, Morphological and Molecular Characterisiation of Erysiphe cichoracearum Causing Powdery Mildew of Okra

Okra (Abelmoschus esculentus (L.) Moench) is a globally important annual vegetable belongs to family malvaceae, it is most broadly distributed vegetable all over the world. Among the fungal diseases affecting okra crop, powdery mildew caused by Erysiphe cichoracearum DC. is the most important disease causing considerable yield losses. The disease was characterized by the appearance of small white powdery specks on upper surface of the lower leaves which enlarged and coalesced forming bigger patches. Later on the disease spread to the upper leaves, coalescing of the white powdery specks and enlargement in their size ultimately resulted in complete coating of white fungal mass on the leaves. The morphological studies of the pathogen in the laboratory revealed, that the mycelium is septate, ectophytic, hyaline and adjacent to the mycelium, basal septum of the conidiophores was seen. The conidiophores were erect, on which conidia were produced either singly or in short chains. The conidia were found cylindrical or barrel in shape, hyaline, non-septate and measured 75.23 µm x 40.65 µm. Molecular characterisation of the native isolate resulted in the DNA amplicon at the region 531 bp. Further, DNA sequence was obtained for ITS Rdna and was deposited in NCBI gene bank. Accession number ‘MW774352’ was obtained and it was confirmed that the causal pathogen of okra powdery mildew of Raichur region is Erysiphe cichoracearum.

The genetic and physiological basis of Arabidopsis thaliana tolerance to Pseudomonas viridiflava.

The opportunistic pathogen Pseudomonas viridiflava colonizes > 50 agricultural crop species and is the most common Pseudomonas in the phyllosphere of European Arabidopsis thaliana populations. Belonging to the P. syringae complex, it is genetically and phenotypically distinct from well-characterized P. syringae sensu stricto. Despite its prevalence, we lack knowledge of how A. thaliana responds to its native isolates at the molecular level. Here, we characterize the host response in an A. thaliana - P. viridiflava pathosystem. We measured host and pathogen growth in axenic infections and used immune mutants, transcriptomics, and metabolomics to determine defense pathways influencing susceptibility to P. viridiflava infection. Infection with P. viridiflava increased jasmonic acid (JA) levels and the expression of ethylene defense pathway marker genes. The immune response in a susceptible host accession was delayed compared with a tolerant one. Mechanical injury rescued susceptibility, consistent with an involvement of JA. The JA/ethylene pathway is important for suppression of P. viridiflava, yet suppression capacity varies between accessions. Our results shed light on how A. thaliana can suppress the ever-present P. viridiflava, but further studies are needed to understand how P. viridiflava evades this suppression to spread broadly across A. thaliana populations.

Biochemical Basis of Abiotic Stress Tolerance in Native Isolates of <i>Beauveria bassiana</i> (Balsamo) Vuillemin from Kerala

A study on the screening of Beauveria bassiana (Balsamo) Vuillemin native isolates for abiotic stress tolerance was carried out at the Department of Agricultural Entomology, College of Agriculture, Vellanikkara, Thrissur, Kerala during 2019-2023. The growth and biochemical parameters of the three native isolates of B. bassiana (BTL1: OP271760, BTL2: OP290199 and PKDE: OP292066) were studied under different abiotic stress conditions viz., temperature, water stress, acidity and salinity. The results revealed that the highest temperature tolerance (40° C) was displayed by the B. bassiana isolate PKDE. It also survived at high water stress (45% polyethylene glycol), acidic (pH2) and saline (1.5 M) conditions. The analysis of biochemical parameters in stress tolerant isolate revealed that the greatest levels of trehalose (2.033± 0.025, 2.043± 0.006 mg/ min/ g of mycelia), catalase (0.0072± 0.007, 0.0032± 0.003 EU/ min/ mg protein) and peroxidase (0.0602± 0.005, 0.0175± 0.017 EU/ min/ mg tissue weight) were observed after exposure to high temperature and water stress, respectively. This shows that exposure to abioticstress and biochemical parameters are closely related and can be used as determinants for evaluating the potential of biocontrol agents.

Quantitative analysis of rhizosphere microbial population obtained from main-croplands in South Sulawesi

The study aims to investigate microbial species and quantify population richness associated with main crop rhizosphere in South Sulawesi. Survey was conducted in two areas including healthy and infected croplands. In each area about 1 ha, samples were collected to consist of 250 g bulk soil of rhizosphere in healthy and infected farms 1 month after transplanting. For analysis, those samples were carried out at the Plant pathology Lab, Department Plant Pest and Disease, Faculty of Agriculture. 10 g bulk soil separation out of 250 g obtained from rhizosphere was sterilized into water 25 mL and sieved 50-100 mesh prior to transfer to growth medium. After that, 4 % (g/mL) potato dextrose agar (PDA) in the petri dish was earlier prepared. The soil mixture (1g/10 mL) was diluted and transferred into a series dilution and parallelly loaded into solid media kept in dark room with at room temperature. Microbiota successfully growing in the solid media were split and transferred into petridish contained PDA for morphological identification and quantified through a series dilution. The study found 23 native fungal isolates consisting of Genera: Rhizopus sp. Phytophthora sp., Fusarium sp., Rhizoctonia sp., Geotrichum, Aspergillus sp., Gliocladium sp., Gongronella sp., and 14 unknown groups of fungi. Three bacterial isolates were discovered as gram-positive bacteria (GPB) in the infected cropland and the other two were gram-negative bacteria (GNB) found in healthy farm. The finding evidenced that population of microbiota ‘bacterial and fungal’ richness was twofold much higher in the healthy farm than infected farm. Bacterial population was the highest in both healthy and infected farms. There is a tendency of the higher fungal population richness, the lower rice disease incidence in croplands, vice versa.

Elucidating the role of media nitrogen in augmenting the production of lignin-depolymerizing enzymes by white-rot fungi.

Indigenous white-rot fungal isolates Schizophyllum commune, Phanerochaete chrysosporium, Ganoderma racenaceum, and Lentinus squarrosulus, demonstrating the ability to depolymerize lignin of the crop residues, were studied for their potential to produce ligninolytic enzymes using modified production media under conditions of limiting and excess nitrogen for higher enzymatic expressions. Secretome-rich media on the investigation confirmed the successful production of lignin-depolymerizing enzymes, viz. laccase, lignin peroxidase, manganese peroxidase, and versatile peroxidase. Production of laccases and peroxidases was statistically significant in nitrogen-limiting media with and without the substrate, across all white-rot fungal cultures at 95% confidence interval. Nitrogen-limiting media with the substrate on analysis extracellularly expressed 99.27 U of laccase and 68.48 U of manganese peroxidase in Schizophyllum commune, while 195.14 U of lignin peroxidase was produced by Phanerochaete chrysosporium. Lentinus squarrosulus expressed 455.34 U of laccase and 357.13 U of versatile peroxidase with 250.09 U of laccase and 206.95 U of manganese peroxidase produced by Ganoderma racenaceum for every milliliter of the media used. Nitrogen-limiting media triggered the production of laccase during the initial stages of growth while the expression of peroxidases was predominant at a later stage. Also, this media evinced increased enzymatic yields with low biomass content compared to nitrogen-excess conditions. The extant study confirmed the positive influence of nitrogen-limiting media in the efficient production of ligninolytic enzymes and their suggestive degradation potential for environmental pollutants, making these enzymes a safe, clean alternative to the use of chemicals and the media to be effective for large-scale production of ligninolytic enzymes. IMPORTANCE Lignin on account of its high abundance, complex polymeric structure, and biochemical properties is identified as a promising candidate in renewable energy and bioproduct manufacturing. However, depolymerization of lignin remains a major challenge in lignin utilization, entailing the employment of harsh treatments representing not only an environmental concern but also a waste of economic potential. Developing an alternative green technology to minimize this impact is imperative. Methods using enzymes to depolymerize lignin are the focus of recent studies. Current research work emphasized the efficient expression of the major lignin-depolymerizing enzymes: laccases, lignin peroxidases, manganese peroxidases, and versatile peroxidases from native isolates of white-rot fungus for several biotechnological applications as well as treatment of crop residues for use as ruminant feed in improving productivity. The importance of nitrogen in augmenting the expression of lignin-depolymerizing enzymes and providing a media recipe for the cost-effective production of ligninolytic enzymes is highlighted.

Unraveling the potential health impact of the interactions between pea hydrolysates/peptides originating under gastric digestion and bile salts

Bile salts (BS) are biological surfactants that have important physiological functions mainly by participating in lipid digestion and intervening in the transport, absorption, and excretion of hydrophobic products. Bile salts have been shown to interact with the products of protein hydrolysis, being this interaction a key point to modulate several physiological processes.The type and size of peptides, released at different times of gastric digestion, could have different implications in these physiological processes modulated by the BS. In the present study we focused on understanding how the interactions of hydrolysates/peptides from native or commercial pea protein isolates with BS (formation of insoluble complexes or the modification of the BS micellar solubilization of poorly soluble molecules) evolve according to their residence time in a static gastric digestion model. The different residence times (10–60 min) would simulate different emptying points in which the partially hydrolyzed pea proteins by pepsin in the stomach are flushed into the duodenum and come into contact with the BS.It is observed that the longer residence times in the stomach the degree of hydrolysis of the pea isolates is greater, producing an increase in the soluble fraction. Both isolates showed a slight tendency to bind BS and form insoluble precipitates. The interaction of the soluble fraction of pea protein hydrolysates with the BS micelles, acted synergistically, increasing the solubilization capacity of oleic acid, taken as a model molecule.Likewise, it is shown that the structural changes of pea proteins due to processing have a profound influence on the interaction with BS and potentially affect the physiological reactions that they modulate.

Biopriming of Tomato Seeds with Native Trichoderma Species for Enhanced Seedlings Vigour

The present research was carried out to investigate the effect of tomato seed biopriming using six native Trichoderma isolates under laboratory conditions. The seeds of tomato were primed in Trichoderma isolates and as a control treatment seeds were treated in sterile distilled water. It was observed that all the six native Trichoderma isolates showed good performance with respect to growth, germination percentage and vigour index of tomato seedlings as compared to control. Among the different Trichoderma isolates tested, T5 isolate showed highest shoot growth (5.44 cm), root growth (3.74 cm), germination percentage (90.0%) and seedling vigour index (826.37) followed by T4 isolate. The lowest shoot growth (4.22 cm), root growth (3.07 cm), germination percentage (56.7%) and seedling vigour index (412.70) were recorded in untreated control.

Endophytic establishment of native Bacillus thuringiensis strain in maize plants and its efficacy against Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

BackgroundBacillus thuringiensis (Bt) is known as the most successful microbial insecticide worldwide used against lepidopteran insect pests in agriculture. Native Bacillus isolate VKK5 showing insecticidal activity against Spodoptera frugiperda (FAW) (J.E. Smith) (Lepidoptera: Noctuidae) was characterized as B. thuringiensis (BtVKK5) on a morphological and molecular basis. Recent research has shown that Bt can be established as an endophytic organism for controlling insect pests. The present work aimed at assessing the colonization of BtVKK5 as an endophyte in five maize cultivars by seed treatment (ST), soil drenching (SD), foliar application (FA) and combination of all methods (ST + SD + FA) and its bioefficacy against neonates of FAW.ResultsEstablishment of inoculated BtVKK5 as endophytes in five maize cultivars, viz. Pusa HQPM7 Improved, Pusa Jawahar Hybrid Maize 1, Pusa Vivek Hybrid 27 Improved (PVH27I), Pusa HQPM5 Improved and DMRH 1301, was confirmed by re-isolating from the leaves of the plant on ampicillin-selected agar plates. Estimation of colony-forming units per gram of leaf showed that there was a significant difference in colonization of the Bt strain among maize cultivars by different inoculation methods. The colonies were further substantiated by the amplification of cry1A and cry1E genes. Bioefficacy studies showed the highest mortality (50%) in the ST + FA + SD inoculation method, followed by ST (40%) in PVH27I. Moreover, growth inhibition was observed in survived larvae on inoculated plants vis-a-vis control.ConclusionEstablishment of Bt strain as an endophyte in maize plants, complemented with insecticidal activity, could possibly lead to an innovative approach to the management of S. frugiperda and other borers.

Evaluation of Indigenous Yeasts Screened from Chinese Vineyards as Potential Starters for Improving Wine Aroma.

Exploitation of the biodiversity of native wine yeast is a means of modifying the sensory characteristics of wine. Samples from different regions in China were analysed to screen native isolates as potential starter cultures. Through morphological and molecular biological analyses, we found six species, belonging to four genera (Hanseniaspora, Saccharomyces, Rhodotorula and Metschnikowia). These species were subjected to stress tolerance assays (ethanol, glucose, SO2 and pH), enzymatic activity tests (sulphite reductase activity, β-glucosidase activity and protease activity) and fermentation tests. Saccharomyces cerevisiae showed a high tolerance to ethanol and completed fermentation independently. Hanseniaspora demonstrated good enzymatic activity and completed sequential fermentation. The fermentation experiment showed that the PCT4 strain had the best aroma complexity. This study provides a reference for selecting new starters from the perspective of flavour enzymes and tolerance and diversifying the sensory quality of wines from the region.

The Optimization, Kinetics Model, and Lab-Scale Assessments of Phenol Biodegradation Using Batch and Continuous Culture Systems

Phenol was considered a severe hazard to all ecosystems even at low concentrations. The bioremediation process is an eco-friendly process for complete phenol degradation and bioelectricity generation. In the present study, a consortium of native isolates was used for phenol biodegradation and bioenergy generation using nano-graphite electrodes. The optimization of nutritional and environmental parameters using batch culture revealed that the optimum conditions for maximum phenol degradation and energy generation were inoculum concentration, 1%; incubation period, 48 h; phenol, 6 ppm; MgSO4, 70 mg/L; K2HPO4, 175 mg/L; and CaCl2, 1 mg/L. Phenol biodegradation reached 93.34% with a power density of 109.419 mW/cm3. A lab-scale bioreactor was used as a continuous culture with aeration rate, agitation speed, and dissolved oxygen of 0.5 v/v/m, 750 rpm, and 30%, respectively. On using the continuous culture, phenol biodegradation and bioenergy production reached 97.8% and 0.382 W/cm3, respectively. A kinetics study using Haldane’s kinetics model reported the best fit to achieve a significant correlation coefficient (R2) value (0.9865) reaching maximum specific growth rate with initial phenol concentration of approximately 9 mg L−1 where the specific growth rates (μ, h−1) varied with different initial phenol concentrations. In conclusion, the native isolated consortium could be considered as an economical and sustainable approach to phenol biodegradation in industrial wastewater as well as bioelectricity generation.

Enhanced laccase activity in Trametes versicolor (L.: Fr.) Pilát by host substrate and copper.

Laccases are appealing biocatalysts for various industrial utilizations. The fungus Trametes versicolor (L.: Fr.) Pilát causes white rot in wood and has been identified as an important fungal laccase producer. To investigate laccase production and activity in T. versicolor, the native isolate was collected from the host (Quercus castaneifolia) in the forests of Guilan province, northern Iran, and then purified and identified using the molecular marker. Its ability to produce laccase enzyme in the presence of different plant substrates including sawdust and wood chips of oak, poplar, and pine was evaluated. Also, the effect of copper as an enzyme inducer was investigated in vitro. The results showed that adding the wood to the culture medium increased laccase production, and among these, oak sawdust had the greatest effect, a 1.7-fold increase from that in the control (4.8 u/l vs. 2.8 u/l). Also, the enzyme extraction time effect on the optimal recovery yield showed that the 5-h enzyme extraction cycle resulted in the highest yield of the enzyme (18.97 u/l). Moreover, adding different concentrations of copper to the fungal culture medium increased the production of laccase, and the highest amount of enzyme (92.04 u/l) was obtained with 3.5 mM of CuSO4 along with oak sawdust. Based on the results, the addition of host wood sawdust ("oak" in this work) and copper particles together stimulates the fungal growth and the laccase production during submerged cultivation of T. versicolor. Therefore, it would be a safe and cheap strategy for the commercial production of laccase by filamentous fungi.

N Vitro Evaluation of Native Isolates of Lecanicillium spp (Berk & Broome) on Hemileia vastatrix

With the objective of developing biological management options for coffee rust, through the characterization and evaluation of native isolates of Lecanicillium spp. The inoculum was obtained from hyperparasitized rust pustules and purified in potato dextrose agar culture medium. Lecanicillium spp. isolates were studied by microscopic, macroscopic, and physiological characterization, as well as In Vitro tests to determine the parasitism of each isolate on uredospores and rust pustules, and the potential for mass production of conidia on organic substrates: soybean, sorghum and rice. Six native isolates of the genus Lecanicillium spp. were obtained from 20 samples, with conidia ranging in size from 2.5 to 7.5 µ in length and from 1.5 to 2 µ in width, in groups or solitary, hyaline in color and cylindrical or ellipsoidal in shape. The size of the phialides ranged from 20 to 28 µ with a base width of 2.5 µ. Phialides were found solitary or in whorls originating from straight conidiophores, the conidia generally in groups of two to six, sometimes solitary. The average radial growth of Lecanicillium spp. 20 days after inoculation was 18 mm in PDA, 15 mm in EMA and 16 mm in SDA. The Majada isolate presented the highest percentage of viability with 99.7% at 22 hours. The isolate La Gotera on the soybean-based organic substrate showed the highest conidial yield of 1.08E+09 per gram of substrate compared to the other substrates and the other isolates. The Jinotega isolate presented the highest parasitism of uredospores in Petri dishes 16.6%. The highest percentage of parasitism on pustules was presented by the isolate La Gotera with 88.3%.

Impact of extraction conditions and seed variety on the characteristics of pennycress (Thlaspi arvense) protein: a structure and function approach

AbstractAs the consumer demand for plant proteins continues to grow, the food industry is seeking novel and sustainable protein sources to incorporate in various food products. Pennycress (Thlaspi arvense), a sustainable cover crop, produces oilseeds high in protein, warranting investigation. Accordingly, protein extraction from pennycress was evaluated under various extraction conditions, using alkaline extraction and salt solubilization coupled with ultrafiltration. Given the superior color and functionality of the salt extracted pennycress protein isolate (PcPI), its production was scaled‐up about two hundred folds in a pilot plant. Furthermore, a new pennycress accession bred to have zero erucic acid (0EA) was evaluated to determine the impact of seed variety on protein characteristics. Structural and functional characterization was performed on PcPI and compared to native (nSPI) and commercial (cSPI) soy protein isolates. Salt extracted PcPI had comparable gel strength to cSPI, three times higher solubility under acidic conditions, and ~1.5 times better emulsification capacity. PcPI extracted from 0EA was mildly different in structure and functionality from that extracted from wildtype pennycress, with the slight variation attributed to genetic variance. Finally, the protein digestibility‐corrected amino acid score (PDCAAS) of the salt extracted PcPI, calculated in vivo (0.72) and in vitro (0.87), was superior or comparable to other plant protein sources. This research provided, for the first time, a comprehensive evaluation of different protein extraction protocols to produce a functional PcPI that can compete with soy protein for various food applications, such as acidic beverages, meat and dairy products, and emulsified systems.