Inoculum Concentration Research Articles

Allelopathic interactions of Carthamus oxyacantha, Macrophomina phaseolina and maize: Implications for the use of Carthamus oxyacantha as a natural disease management strategy in maize.

Fungicides are used to control phytopathogens but all these fungicides have deleterious effects. Allelopathic interactions can be harnessed as a natural way to control the pathogens but there are no reports that show the allelopathic interactions of donor plant, recipient crop, as well as the target plant pathogen and the material used for inoculum production. So, in the present study, the suitability of Carthamus oxyacantha M. Bieb. was assessed against Macrophomina phaseolina, the cause of charcoal rot in maize. Among the various treatments in pot experiment, a negative control, 3 concentrations of inoculum (1.2×105, 2.4×105, and 3.6×105 colony forming units (CFU) mL-1, 3 concentrations (0.5, 1.0, and 1.5% w/w) of C. oxyacantha along with an autoclaved M. phaseolina (Mp) and C. oxyacantha alone were included to investigate their allelopathic effects on maize, not investigated earlier. Maximum suppression of the disease was observed by 1.5% (w/w) concentration of C. oxyacantha. Soil amendment with C. oxyacantha significantly suppressed the disease incidence (DI) and disease severity index (DSI) in charcoal rot of maize up to 40 and 55%, respectively over the strongest level of inoculum (Mp3). C. oxyacantha not only reduced area under disease incidence progress curve (AUDIPC) and area under disease severity progress curve (AUDSPC), but also improved the morphological, biochemical and physiological parameters of maize. The maximum increase of 48, 65, and 75% in values of shoot length (SL), shoot dry mass (SDM), and root dry mass (RDM), respectively was observed by application of the highest concentration of C. oxyacantha in the treatment Mp1+Co3, over infested control (Mp1). Photosynthetic pigments, such as chlorophyll a, chlorophyll b and carotenoids were increased to 58, 64, and 46%, respectively over Mp1, by the application of C. oxyacantha. Carbon assimilation rate (A), stomatal conductance (gs), rate of transpiration (E), and internal carbon dioxide concentration (Ci) were significantly increased to 58, 48, 48, and 20%, respectively over infested control (Mp3), by application of C. oxyacantha concentration 1.5 (w/w). Moreover, defense enzymes like superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities were boosted up to 27, 28, and 28% over Mp3, respectively. Positive allelopathy of C. oxyacantha towards maize and negative allelopathy towards M. phaseolina makes C. oxyacantha a suitable candidate for charcoal rot disease control in maize.

Optimization of Citrus Pulp Waste-Based Medium for Improved Bacterial Nanocellulose Production.

Bacterial nanocellulose (BC) has attracted significant attention across a wide array of applications due to its distinctive characteristics. Recently, there has been increasing interest in leveraging waste biomass to improve sustainability in BC biogenesis processes. This study focuses on optimizing the citrus pulp waste (CPW) medium to enhance BC production using Komagataeibacter sucrofermentans. The screening of initial medium pH, yeast extract, CPW sugar and inoculum concentrations was conducted using the Plackett-Burman design, with BC yield (mgDW/gCPW) as the model response. The significant parameters, i.e., CPW sugars and yeast extract concentrations, were optimized using response surface methodology, employing a five-level, two-factor central composite design. The optimized CPW-based growth medium resulted in a final yield of 66.7 ± 5.1 mgDW/gCPW, representing a 14-fold increase compared to non-optimized conditions (4.3 ± 0.4 mgBC/gCPW). Material characterization analysis indicated that the produced BC showed high thermal stability (30% mass retained at 600 °C) and a crystallinity index value of 71%. Additionally, to enhance process sustainability, spent baker's yeast hydrolysate (BYH) was assessed as a substitute for yeast extract, leading to a final BC titer of 9.3 ± 0.6 g/L.

Removal of Nitrogen, Phosphorus, Organic Matter, and Heavy Metals from Pig-Farming Wastewater Using a Microalgae-Bacteria Consortium.

Wastewater generated by the pork industry urgently requires the implementation of low-cost, high-benefit, and efficient treatment systems. Accordingly, a microalgae-bacteria consortia-based treatment system is proposed for the removal of contaminants released, by the pork-producing industry, in swine wastewater. In this study, different inoculum concentrations of the microalgae-bacteria consortium were tested to document variation in the removal of nutrients from the wastewater. At varying concentrations, it was efficient and did not present a significant difference in the removal kinetics. The treatment with the greatest amount of inoculum removed close to 87% of total nitrogen, approximately 70% of orthophosphate, and 77% of chemical oxygen demand. Removals of 84% iron, 44% copper, and 48% manganese were also obtained. These results demonstrate that microalgae-bacteria consortia are an economically viable and environmentally desirable option for the efficient treatment of wastewater from the pork industry.

Microbial depolymerization of Kraft lignin for production of Vanillic acid by indigenous ligninolytic strains

Lignin is a potential renewable source for the production of many value-added bio-products through bacterial depolymerization. In this study, Kraft lignin (KL) was depolymerized by indigenous potential ligninolytic strains to obtain the optimum amount of Vanillic acid. Initially, fifteen bacterial strains were isolated from decaying wood mixed soil to assess their lignin degradation efficiency. Five potential lignin-degrading microbes (RW-B2, RW-B4, RW-B9, RW-B11 and RW-B15) were identified by nutrient enrichment technique. RW-B15 was observed as a dominant strain sharing a 99 % resemblance to Bacillus megaterium sp. Optimum temperature and bacterial inoculum concentration were noted as 35 °C and 1 %, respectively. Mixed microbial culture of five potential ligninolytic strains showed better KL degradation than pure culture due to different metabolic capacities, enzymatic mechanisms and synergetic impact among the association members. The KL degradation study was conducted with different KL concentrations (500–2000 mg/l) at optimum temperature using 1 % inoculums. The production of Vanillic acid increased from 60.1 to 199.9 mg/l with increasing concentration of KL from 500 to 2000 mg/l. The maximum production of Vanillic acid was obtained on 3rd day of degradation and it decreased thereafter which is probably due to an increase in microbial toxicity and enzymatic activity. However, the COD level continuously decreased for all KL concentrations with degradation time till the last day. The pH of the KL solution slightly decreased on 3rd day due to the acidic nature of Vanillic acid. GC-MS analysis confirmed the presence of Vanillic acid and showed the presence of other monomeric compounds formed after KL degradation.

Caproic acid production from short-chained carboxylic acids produced by arrested anaerobic digestion of green waste: Development and optimization of a mixed caproic acid producing culture

Caproic acid is an important compound for producing a variety of chemicals and a potential precursor for Sustainable Aviation Fuels (SAF). This study aimed at developing a stable mixed culture producing caproic acid using short-chain carboxylic acids (SCCAs) derived from arrested anaerobic digestion (AAD) of green waste and optimizing chain elongation (CE) conditions. The results showed that the mixed culture was dominated by Clostridium sensu stricto 12 (53.09 %), optimally producing caproic acid at 37 °C, pH 7.20, with a 15 % inoculum concentration. Under these conditions, 75.59 % of the consumed electrons contributed to caproic acid formation. Gradual ethanol feeding in bioreactor experiments resulted in caproic acid titer of 13.36 g/L, with carbon conversion efficiency (CCE) of 81.91 % and electron transfer efficiency (ETE) of 76.39 %, surpassing batch experiments without gradual ethanol addition. These findings demonstrate that the effectiveness of a mixed culture can be improved, resulting in increased caproic acid production.

Production of Bioactive Peptides from Tartary Buckwheat by Solid-State Fermentation with Lactiplantibacillus plantarum ATCC 14917.

Buckwheat is a valuable crop that contains various nutrients and functional components. Tartary buckwheat peptide is a protease-hydrolyzed protein with a wide range of physiological functions. Tartary buckwheat peptide produced through microbial fermentation can decrease the enzymatic digestion of buckwheat protein, which contributes to the bitter taste, and improve both the flavor and texture of buckwheat peptide products. In this study, microbial fermentation using probiotics was employed to prepare Tartary buckwheat peptides, and the preparation process was optimized. Based on single-factor experiments, the polypeptide content in the fermentation solution initially increased and then decreased with varying water content, inoculum concentration, glucose addition, fermentation temperature, fermentation time, and potassium dihydrogen phosphate addition. According to the response surface methodology, the maximum peptide content was achieved under fermentation conditions of 60.0% moisture content, 12.87% inoculum ratio, 2.0% glucose, and a fermentation temperature of 30.0 °C, with an actual value of (22.18 ± 1.02) mg/mL. The results show that fermentation with Lactiplantibacillus plantarum produces higher peptide levels and is safer than other microbial fermentation methods.

Microbially Induced Calcium Carbonate Precipitation UsingLysinibacillussp.: A Ureolytic Bacteriumfrom Uttarakhand for Soil Stabilization.

Microbially induced calcium carbonate precipitation (MICP) is a soil remediation method that has emerged as a viable and long-term solution for enhancing soil mechanical qualities. The technique of MICP that has been extensively researched is urea hydrolysis, which occurs naturally in the environment by urease-producing bacteria as part of their fundamental metabolic processes. The objectives of the current study include screening and identifying native ureolytic bacteria from soil in Uttarakhand, optimizing growth factors for increased urease activity, and calcite precipitation by the bacteria using response surface methodology. Additionally, it was assessed how well the isolated bacteria in the medium biomineralized when using synthetic media and cheaper alternatives such as cow urine and eggshell as sources of urea and Ca2+, respectively. The isolated strain identified as Lysinibacillus sp. was found to be the very active strain after soil samples were screened for ureolytic bacteria. It was discovered that optimization studies with values of pH 8, urea concentration (0.8M), inoculum concentration (3%), and incubation time (48h) yielded a higher activity of 33.7 U/mL (threefold increase), and a higher calcium carbonate precipitation (enzyme activity: 10.96 U/mL, pH: 8.92, soluble Ca2⁺: 25.53mM and insoluble Ca2⁺: 0.856g). The calcite precipitation in broth media supplemented with ready-made substrates and alternative sources demonstrated a similar result of increased pH and ammonia release. Thus, the current study successfully paves the way for several possibilities to stabilize the slopy soils prone to landslides and erosion in Uttarakhand and pinpoint an economic approach through biomineralization.

PENGARUH METODE FERMENTASI TERHADAP PENINGKATAN KANDUNGAN KIMIA DAN AKTIVITAS FARMAKOLOGI PADA BEBERAPA TANAMAN: Artikel Review

Fermentation is a process that involves the chemical transformation or breakdown of complex organic substances or other food components into simpler compounds through the action of natural enzymes and fermenting microorganisms. The purpose of this literature review is to explore the impact of fermentation methods on the enhancement of phytochemical content and pharmacological activity in various plants. Journal searches were conducted on Google Scholar, PubMed, and ScienceDirect. The results revealed that fermentation methods can increase the chemical content and pharmacological activity of a plant. Microorganisms that are frequently used in the fermentation process, such as Bacillus subtilis and actobacillus brevis, can increase the total phenol content and enhance antioxidant activity. Factors influencing the fermentation process in improving the chemical content and pharmacological activity of a plant include treatment methods, duration of fermentation (incubation), microorganisms used, and the concentration of inoculum used.

Spray inoculation and image analysis-based quantification of powdery mildew disease severity on pea leaves

Pea (Pisum sativum) is an important agricultural legume crop, but powdery mildew disease caused by the biotrophic fungus Erysiphe pisi regularly limits its annual yield. Assays to evaluate the efficacy of potential antifungal compounds or resistance genes for disease control require a simple fungal inoculation method that provides control over the initial inoculum concentration and enables uniform inoculum distribution within a leaf and across replicates as well as a method for the quantitative assessment of disease severity. Here, we present an easy spray inoculation method for the uniform distribution of a defined concentration of E. pisi conidia on the leaves of pea plants and a semi-automated image analysis-based quantification of disease symptoms. The uniformity in conidial distribution was validated using a novel grading system termed the uniformity index. In addition, RT-qPCR was used to validate the reproducibility of the spray inoculation method and image analysis-based disease quantification. These procedures permit the accurate quantification of powdery mildew disease severity at macroscopic and molecular levels.•Uniform and reproducible inoculum distribution on leaves using a simple and inexpensive spray device•Rapid and reproducible quantification of powdery mildew disease symptoms using open-source software without the requirement of computational expertise

The effects of irrigation on the survival of Clostridium sporogenes in the phyllosphere and soil environments of lettuce

This study aimed to address the gap in knowledge regarding the fate of foodborne pathogens within agro-ecosystems. It specifically focused on the surrogate microorganism Clostridium sporogenes, which was introduced into lettuce-producing environments via surface and spray irrigation methods, respectively. The concentration of C. sporogenes in the rhizosphere, phyllosphere, and non-rhizosphere soil was quantified by quantitative polymerase chain reaction (qPCR) over a 42-day trial. The surface irrigation method exhibited a more noticeable contamination effect on the soil environments, compared to the phyllosphere. The results indicated a noticeable increase in C. sporogenes concentrations during the initial 22 days, with a 10.4-fold rise (0.39–4.05 log copy numbers/g soil) in the rhizosphere and 1.9-fold increase (2.97–5.59 log copy numbers/g soil) in the non-rhizosphere. However, concentrations in both soil environments subsequently decreased, falling below the initial inoculum concentration by the end of the trial. In contrast, the spray irrigation method resulted in most of the contamination being localised on the lettuce phyllosphere, with a high C. sporogenes concentration of 9.09 log copy numbers/g leaves on day 0. This concentration exponentially decreased to a minimal 0.019 log copy numbers/g leaves by day 32. Although concentrations in both soil environments decreased over time, trace concentrations of C. sporogenes were detectable at the end of the trial, posing a potential hazard to the microbiological safety of postharvest produce. These findings shed light on the dynamics of C. sporogenes in agro-ecosystems and underscore the importance of irrigation practices that ensure the safety of those who consume fresh produce.

Harnessing Packed-Bed Bioreactors’ Potential in Solid-State Fermentation: The Case of Beauveria bassiana Conidia Production

The packed-bed bioreactor is among the most promising reactor configurations for solid-state fermentation. However, the bed thickness poses several limitations involving mass and energy transfer, heat generation, and the homogeneity of the material, hampering its development at the industrial scale. Fungi are among the most promising microorganisms used in this configuration; however, only polypropylene bags and trays are used at the industrial scale. In this work, Beauveria bassiana is used to demonstrate the potential of solid-state fermentation for conidia production. A scale-up from 0.5 L to 22 L is presented, starting with substrate selection, optimization via design of experiments and 22 L batches. The optimized parameters were 70% moisture, 6.5 × 106 conidia mL−1 inoculum concentration, 20 mL min−1 airflow, 25 °C; temperature, and 40 C/N ratio. After optimization, beer draff was chosen as the preferred substrate for scale-up. Air-filled porosity was found to be the key parameter in fungal solid-state fermentation scale-up, establishing values of around 80% as necessary for fungal conidia production when working in a 22 L packed-bed bioreactor. When compared with the tray bioreactor, the packed bed obtained higher conidia production due to its better use of the total reactor volume. Our study harnesses the potential of the packed-bed bioreactor and serves as a base for further scale-up to industrial scale.

Bio-process optimization for developing a turmeric (Curcuma longa Linn.) beverage fermented with functional lactic acid starter cultures

Turmeric, scientifically known as Curcuma longa, is a herbaceous plant characterized by its rhizomatous nature with remarkable chemical composition and biologically active compounds. Lactic acid bacteria (LAB) have been observed to break down complex polyphenols into simpler, more bioactive compounds through fermentation. The success of the fermentation process relies on various factors to achieve the desired end product. This study's main goal was to assess the feasibility of using turmeric as a fermentable substrate for LAB, with the intention of creating a non-dairy fermented beverage. The investigation delved into the impact of several fermentation parameters, namely Fermentation Temperature, pH (Lemon juice concentration), Inoculum concentration, and Substrate concentration (Turmeric concentration), on the phytochemical and antioxidant properties of the lactic acid-fermented turmeric beverage (FTB). Statistical analysis revealed that a quadratic polynomial model could effectively illustrate how these fermentation parameters influenced the beverage's phytochemical and antioxidant qualities. Visualization through response surface plots revealed that these independent variables significantly influenced the beverage's total phenolic content, total flavonoid content, and antioxidant properties. Optimal fermentation conditions were identified to yield the highest levels of phenolic, flavonoid, and antioxidant content. These conditions included a Fermentation Temperature of 37.45 °C, a pH of 5.62, an Inoculum concentration of 5.12%v/v, and a Substrate (turmeric) concentration of 2.28%w/v. Under these precise conditions, experimental results closely aligned with predicted values for total phenolic content (57.46mg/100 ml), total flavonoid content (51.48mg/100 ml), and total antioxidant activity (72.24%). The overall acceptability of the fermented turmeric beverage reached a high 98.10%. Notably, the FTB exhibited significantly improved attributes such as astringency, flavor, taste, and overall acceptability when compared to the non-fermented turmeric beverage (NFTB), with statistical significance (P < 0.05).

Stem cells of Impatiens tinctoria A.Rich tuber and antioxidant activity of their extracts

The use of plant stem cell extracts as active ingredients in cosmetic formulations has gained popularity recently, highlighting the need to establish Impatiens tinctoria A. Rich in vitro cultures in order to prepare bioactive stem cell extracts. This study is aimed at establishing cell suspension culture and evaluates the antioxidant activity of the stem cell extract. In order to initiate callus and cell suspension cultures, tuber explants were inoculated onto Murashige and Skoog (MS) media containing 2,4-D (0.5–2 mg/L) and BAP (0–2 mg/L). Optimal hormone concentrations of 2 mg/L 2,4-D and 1.5 mg/L BAP were sufficient to produce callus. The obtained callus was utilized as the inoculum to start a cell suspension culture for the production of stem cell extracts. High biomass accumulation was obtained at 30 g/L sucrose concentration and 6g inoculum size. The stem cell extract had a total phenolic content of 4.6 µgGAE/mL and a flavonoid content of 190.96 µgQE/mL. DPPH scavenging activity of 95.82% and the IC50 value of 37.54 µg/mL was detected for the stem cell extract. The study indicated that the suspension cultures of I. tinctoria A. Rich have the potential to produce stem cell extracts with increased flavonoids content and antioxidant activity.

Efficient treatment of actual biogas slurry by Chlorella sorokiniana: Nutrient recovery and biomass production

Microalgae have received widespread attention for their effectiveness in treating highly concentrated organic wastewater, not only for the effective removal of pollutants, but also for the preparation of biofuels and high-value products. This study investigated that the efficient purification process and mechanism of Chlorella sorokiniana on actual biogas slurry, including nutrient removal and biomass production. The results showed the C. sorokiniana grew well with a biomass of 742.35 ± 1.72 mg/L at pH 9, an inoculum concentration of 60 mg/L and 24 h of continuous light for 12 days. The recirculating experiments showed that after three incubations of the biogas slurry, the removal efficiency of COD, TN, NH4+-N, TP and PO43−-P were 89.11 %, 89.30 %, 97.26 %, 95.39 % and 96.43 %, respectively, and the total biomass of microalgae was 1015.87 mg/L. The contents of lipids, proteins, carbohydrates and photosynthetic pigments in C. sorokiniana cultured in biogas slurry were 26.36 %, 31.34 %, 30.26 % and 16.31 mg/L, respectively. It was increased by 6.21 %, 7.24 %, 2.74 % and 12.82 mg/L compared to the control, respectively. SEM results showed that the surface of C. sorokiniana mosaic with a large number of bacteria, and the cultivation of C. sorokiniana promoted the relative abundance for Proteobacteria, Cyanobacteria and Bacteroidota. Cultivation of C. sorokiniana in the actual biogas slurry constituted a good algae-bacterial symbiosis system, which effectively promoted the process of wastewater purification. This study provided an applied reference for the efficient treatment of actual wastewater by microalgae and its potential for resources utilization.

Impact of overhead evaporative cooling, canopy location, sunlight exposure, inoculation level, region, and growing season on the survival of generic Escherichia coli on in-field Fuji apples.

The survival of inoculated Escherichia coli on Fuji apples in Washington State orchards was studied, considering evaporative cooling, canopy location, year, and region, with the examination of sunlight exposure and inoculation levels in year 2. Rifampicin-resistant E. coli was applied to Fuji apples. Initial concentrations for the high-inoculation study were 7.4±0.3 log10 CFU per apple and 3.4±0.3 log10 CFU per apple for the low-inoculation study. Enumeration of E. coli was conducted at 0, 2, 10, 18, 34, 42, 58, 82, 106, and 154 h after inoculation. Results were analyzed using Tukey's honest significance difference test and a log-linear model. Log-linear, Weibull, and biphasic models characterized E. coli die-off patterns for high and low inoculations. The application of evaporative overhead cooling water did not significantly influence E. coli survival on Fuji apples; inoculation level and sunlight exposure were significant factors in a log-linear model. Escherichia coli decreased by 5.5±1.3 and 3.3±0.4 log10 CFU per apple for high and low-inoculated apples, respectively, by 154 h. The biphasic model best explained the die-off pattern for high and low-inoculated Fuji apples. Overhead evaporative cooling, a useful fruit quality practice, did not impact the survival of generic E. coli on Fuji apple surfaces. The significant impact of sunlight exposure and inoculation levels on die-off highlights the importance of ultraviolet radiation in risk reduction and the need for various inoculum concentrations in preharvest field studies.

Epidemiology of cryptococcal meningitis and fluconazole heteroresistance in Cryptococcus neoformans isolates from a teaching hospital in southwestern China.

Cryptococcal meningitis (CM), a common and serious opportunistic infection mostly caused by Cryptococcus neoformans, is primarily treated with fluconazole. Nevertheless, Cryptococcus neoformans strains that undergo repeated exposure to azoles can gradually acquire heteroresistance to fluconazole. The management of this specific CM infection poses a substantial challenge. Determining a globally accepted definition for fluconazole heteroresistance and developing effective and prompt methods for identifying heteroresistance is of utmost importance. We collected data on the clinical and epidemiological characteristics of patients diagnosed with CM. All the available Cryptococcus neoformans strains isolated from these patients were collected and subjected to antifungal susceptibility testing and evaluation of fluconazole heteroresistance. AIDS was present in 40.5% of the patients, whereas 24.1% did not have any underlying diseases. Patients with chronic diseases or impaired immune systems are susceptible to infection by Cryptococcus neoformans, a fungus that frequently (39.6%, 19/48) shows heteroresistance to fluconazole, as confirmed by population analysis profile (PAP).IMPORTANCEFluconazole heteroresistance poses a significant threat to the efficacy of fluconazole in treating cryptococcal meningitis (CM). Unfortunately, the standard broth microdilution method often misses the subtle percentages of subpopulations exhibiting heteroresistance. While the population analysis profile (PAP) method is esteemed as the gold standard, its time-consuming and labor-intensive nature makes it impractical for routine clinical use. In contrast, the Kirby-Bauer (KB) disk diffusion method offers a simple and effective screening solution. Our study highlights the value of KB over PAP and minimum inhibitory concentration (MIC) by demonstrating that when adjusting the inoculum concentration to 1.0 McFarland and subjecting samples to a 72-hour incubation period at 35°C, the KB method closely mirrors the outcomes of the PAP approach in detecting fluconazole heteroresistance. This optimization of the KB method not only enhances assay efficiency but also provides a blueprint for developing a timely and effective strategy for identifying heteroresistance.

Production of Amylase Enzyme by Aspergillus and Fusarium Species using Sugar Cane Bagasse

Study’s Novelty/Excerpt This study presents insights into the cost-effective production of amylase enzymes using sugar cane bagasse as a substrate, showcasing a significant advancement over traditional synthetic starch substrates. By optimizing production parameters such as incubation time, substrate and inoculum concentrations, pH, and temperature, the research demonstrates the superior amylase yield of Aspergillus niger, Aspergillus flavus, and Fusarium spp. under specific conditions. This work not only highlights the potential of using waste materials for industrial enzyme production but also emphasizes the need for further exploration of the isolates' identities and the industrial applications of the extracted enzymes. Full Abstract Amylases are hydrolytic enzymes produced by some microorganisms and utilized in the hydrolysis of starch. This study aimed to determine the ability of certain fungal isolates isolated from wastes to synthesize the amylase enzyme utilizing synthetic soluble starch and sugar cane bagasse as substrates. Aspergillus niger, Aspergillus flavus, and Fusarium spp., previously identified to have amylolytic activity, were used for the research. The submerged fermentation process was used to produce amylase, with basal medium and sugar cane bagasse as substrates. The incubation time, substrate and inoculum concentrations, pH, and temperature were all optimized. The dinitrosalicylic acid reagent (DNS) technique was used to determine the activity of the amylase generated. Initial production of amylase using soluble starch (20 g (w/v)) as substrate at room temperature and pH 7.0 shows that all the isolates produce amylase better when their concentration (3%) is high but have different incubation periods of 96 hr for Aspergillus niger (8.65±0.21 U/mL/minutes) and Fusarium spp (7.15±0.07 U/mL/minutes), while Aspergillus flavus (7.30±0.14 U/mL/minutes) requires an extended incubation period of 144 hr to produce the product. Further production using sugar cane bagasse and optimization of production parameters of the isolates reveals that Aspergillus niger (4.35±0.07 U/mL/minutes) has an optimum incubation period of 120 hours, an inoculum concentration and substrate concentration of 2% each, and a pH of 6, Aspergillus flavus (6.40±0.28 U/mL/minutes) has an optimum incubation period of 144 hours, with inoculum and substrate concentration of 3% each at neutral pH, Fusarium spp (6.80±0.28 U/mL/minutes) has an optimum incubation period of 168hr., inoculum concentration of 3%, substrate concentration of 2% and a neutral pH-7 and all the isolates have their best yield at temperature of 30oC. In conclusion, using cheap and readily available sugar cane bagasse can be a more cost-effective option for expensive synthetic starch substrates used in amylase synthesis. The study suggests further investigation into the isolates' identities and the extracted enzyme's industrial application.

Culture of sheep poxvirus in a 3D Vero cells culture model

In the article the production of a three-dimensional culture of Vero cells using the methods of “hanging drop” and roller cultivation was described. The resulting spheroids remain viable for more than four days. For the formation of large spheroids with good proliferative activity, the inoculum concentration should be 200000 cells/ml. The additional study of the cell proliferation index in spheroids showed that cell growth was 3.5 times on the second day. A comparative study of the biological activity of the sheep poxvirus in 3D cell culture was carried out in comparison with traditional2D cultivation. After infection of the spheroids with sheep poxvirus in the first passage, the virus titer was 5.33±0.04 lg TCID50/ml. At the second and third passages, the biological activity of the virus increased to 6.33±0.04 and 6.41±0.04 lg TCID50/ml, respectively. Considering these data, three-dimensional culture allows for obtaining much cell biomass with high biological activity compared to the traditional culture method.

Development and application of the fungal plant pathogen Colletotrichum shisoi to control invasive Perilla frutescens

Inadvertently introduced plant pathogens that infect invasive plant species might be effective weed biological control agents if developed for redistribution or augmentation of naturally occurring populations. Colletotrichum shisoi is likely an inadvertent introduction to the United States where it causes disease on invasive perilla mint (Perilla frutescens). This study reports on the development and application of C. shisoi as a biological control agent. The effects of dew period on infection probability and of inoculum concentration on perilla biomass production were determined to identify a threshold dose and dew period required for effective biological control activity. Under controlled conditions, application of the pathogen reduced perilla biomass, flower production, and interspecific competitive ability. In a replicated field trial, both the introduction and augmentation of C. shisoi populations caused high perilla mortality and moderate changes in plant community composition over one growing season. Additionally, a series of experiments were performed to evaluate methods for the production and preservation of C. shisoi spores. Overall, the pathogen was found to be an effective antagonist of perilla mint when applied inundatively under appropriate conditions. It may be possible to produce the pathogen in mass for redistribution across the invaded range of perilla in North America, but further research is needed for adequate preservation of inoculum during transport and application.

Bioproduction of high-value raspberry ketone by submerged fermentation of Nidula niveo-tomentosa

Raspberry ketone (RK) is a high-value bioactive component in the growing demand for natural compounds in food and flavour industries. However, limited production persists due to low-yield microorganisms and complex biosynthetic pathway. Here, an Nidula niveo-tomentosa fungi-based fermentation system was developed to investigate and optimize the cultivation parameters for natural RK production. While optimizing glucose and phenylalanine concentrations ensured sufficient substrate supply, it unexpectedly induced stress on the substrates. Despite having minimal impact on biomass growth, UV-A radiation effectively boosted RK biosynthesis, but also reaching a ceiling with extended exposure times. Younger precultures exhibited higher specific productivity, older cultures ultimately yielded more RK due to their higher inoculum concentration. Mycelial fungi, compared to fungal pellets, outperformed in RK production, likely facilitated by enhanced nutrient uptake and bioproduct transport. Ultimately, the combination of optimized parameters unlocked a peak RK yield of 154.4 mg/L, underscoring the remarkable potential for natural RK production.