Spore Color Research Articles

Neogene–Quaternary paleoenvironments and kerogen assessment of the NDO B-1 well, offshore Nile Delta, Egypt, Eastern Mediterranean: palynological evidence

Palynofacies and palynological investigations conducted on the Neogene–Quaternary succession from the NDO B-1 well, located in the offshore Nile Delta, Egypt, in the Eastern Mediterranean, suggest generally shallow marine (neritic) conditions. These environments are manifested by the overall palynofacies composition and the occurrence of dinoflagellate cysts (e.g., Spiniferites spp., Lingulodinium spp., Hystrichokolpoma spp., Homotryblium spp. and Selenopemphix spp.). Neritic environments are suggested for the lower and middle Miocene Sidi Salim, and the Pliocene to Pleistocene upper Kafr El Sheikh, El Wastani and Mit Ghamr formations, while shallower, coastal to inner neritic settings were interpreted for the late Miocene (Qawasim and Rosetta formations) and early Pliocene (Abu Madi and lower Kafr El Sheikh formations). Anoxic conditions existed during the deposition of the studied well succession, which can be seen from the occurrence of imprints of pyrite crystals and some types of oxygen-sensitive dinoflagellate cysts. The palynofacies fluctuated repeatedly between Amorphous Organic Matter (AOM)-dominated and phytoclast-dominated intervals, of kerogen types II and III, respectively. The spore coloration index (SCI) of indigenous thin-walled palynomorphs confirms thermally mature sediments, generative of dry gas and wet gas/condensates. Reworking during the deposition of the upper Sidi Salim, Qawasim and Rosetta formations is inferred from the occurrence of Cretaceous dinoflagellate cysts and pollen.

Palynological, palynofaciological and organic geochemistry analysis of oligocene microclastics sediments from the tremembé formation - São Paulo State, Brazil

Samples of outcrops from the mining companies Extrativa Santa Fé Ltda and Aligra - Indústria e Comércio de Argila Ltda provided the base material for this investigation into palynological, palynofaciological and organic geochemistry analyses of the Taubaté Basin, São Paulo State. The sediments belong to the Tremembé Formation and comprise microclastic rocks. The Tremembé Formation is known for its rich fossil record and clay mineral content, widely used as raw material for various industrial processes. The generating potential of the sediments was evaluated through qualitative and quantitative analyses of organic content, percentage of total organic carbon (TOC), and Rock-Eval pyrolysis.Furthermore, using transmitted light optical microscopy, observation of the palynological content allowed the identification of characteristic species in terms of age and thermal maturation through the Spore Color Index (SCI) and depositional paleoenvironment.Palynofacies were individualized via reflected light optical microscopy, and together with Rock-Eval pyrolysis data, the quality and type of kerogen were determined. The organic content of the two mining companies shows a predominance of amorphous, globose, and dispersed organic matter of lacustrine origin. Moreover, it is composed mainly of the genera Botryococcus and Pediastrum algae. Palynological associations allowed the section to be temporally positioned in the Oligocene.The abundance of bisaccate pollen grains attributable to conifers, represented mainly by the species Podocarpidites marwickii and Dacrydiumites florinii, combined with the presence of spores, suggests a temperate paleoclimate with humid niche conditions. The pyrolysis results and microscopic observation of the organic content in fluorescence mode show that deposition occurred under anoxic conditions, allowing better preservation of organic matter with high potential for generating hydrocarbons.

Upper Cretaceous (Cenomanian) palynostratigraphy and palynofacies of the Shushan Basin, North Egypt

This study provides an updated quantitative analysis and prospective paleoenvironment reconstruction of the Tut oilfield, Shushan Basin, North Egypt to evaluate the hydrocarbon reservoirs in space and times for further development plans and modeling in the Tethyan region. Two sporomorph interval zones (Classopollis brasiliensis and Afropollis jardinus), and one total foraminiferal Range Zone (Thomasinella punica) are proposed. Three palynofacies assemblages are differentiated using cluster analysis of the different palynofacies parameters. The paleoenvironmental conditions during the Cenomanian were reconstructed. Palynofacies assemblage I of the Baharyia Formation suggests a marginally dysoxic-oxic basin environment with a common occurrence of ostracods and terrestrial organic matter, while palynofacies assemblage II reflects the high abundance of dinoflagellate cysts, suggesting a suboxic-anoxic middle neritic environment. Palynofacies assemblage III of the upper part of the Abu Roash G Member represents a relatively deep water inner-middle neritic environment. Three 3rd order significant sequences separated by two hiatus surfaces (Ce3 and Ce4) are described and correlated with the global eustatic sea-level. The hydrocarbon evaluation results show that the samples from the Abu Roash G Member contain oil-prone material of kerogen type II, while the samples of the Baharyia Formation are characterized by kerogen type III (gas-prone). Spore coloration analysis reveals that the samples from the studied units are too immature to produce gas or oil and are ineffective as sources of hydrocarbons.

Integrating Palynofacies Analysis and Spore Coloration for Assessing Thermal Maturity and Hydrocarbon Potential in Cretaceous Rocks: Safir-N-2 Well, Egypt

Integrating Palynofacies Analysis and Spore Coloration for Assessing Thermal Maturity and Hydrocarbon Potential in Cretaceous Rocks: Safir-N-2 Well, Egypt

Identification of the chaA and fwA Spore Color Genes of Aspergillus nidulans.

Wild-type Aspergillus nidulans asexual spores (conidia) are green due to a pigment that protects the spores against ultraviolet light. The pigment is produced by a biosynthetic pathway, the genes of which are dispersed in the genome. The backbone molecule of the pigment is a polyketide synthesized by a polyketide synthase encoded by the wA gene. If wA is not functional, the conidia are white. The polyketide is modified by a laccase encoded by the yA gene and inactivation of yA in an otherwise wild-type background results in yellow spores. Additional spore color mutations have been isolated and mapped to a locus genetically, but the genes that correspond to these loci have not been determined. Spore color markers have been useful historically, and they remain valuable in the molecular genetics era. One can determine if a transforming fragment has been successfully integrated at the wA or yA locus by simply looking at the color of transformant conidia. The genes of the potentially useful color loci chaA (chartreuse conidia) and fwA (fawn conidia) have not been identified previously. We chose a set of candidate genes for each locus by comparing the assembled genome with the genetic map. By systematically deleting these candidate genes, we identified a cytochrome P450 gene (AN10028) corresponding to chaA. Deletions of this gene result in chartreuse conidia and chartreuse mutations can be complemented in trans by a functional copy of this gene. With fwA, we found that the existing fawn mutation, fwA1, is a deletion of 2241 base pairs that inactivates three genes. By deleting each of these genes, we determined that fwA is AN1088, an EthD domain protein. Deletion of AN1088 results in fawn conidia as expected. Neither deletion of chaA nor fwA restricts growth and both should be valuable target loci for transformations. Combinations of deletions have allowed us to investigate the epistasis relationships of wA, yA, chaA and fwA.

Determination and Comparison of Total Aflatoxin Levels in Groundnuts from Four Major Markets in Lagos State, Nigeria

Aflatoxins (Aspergillus flavus toxins) are poisonous substances produced by some fungi on crops, foods, and feeds. The study was carried out to determine and to compare total aflatoxin levels in groundnuts sold in Lagos markets, Nigeria. Microbiological and toxicology tests were carried out on raw, boiled, and roasted groundnuts from the same source. The microbiological test was carried out to detect the fungi that produce aflatoxins as their secondary metabolite. The groundnuts samples were cultured on Potato Dextrose Agar (PDA). The isolates were identified using standard microbiological methods, characteristics such as presence of spores, shape, colour of spores and presence of septa were used in identification. Aspergillus flavus (75%; percentage of occurrence) was the most frequently isolated fungus from the groundnut samples. The other contaminant isolated from the samples were Aspergillus niger (25%). The toxicology analysis was carried out to determine the production of aflatoxins and the level present in the groundnut. This was carried out using a Romer Mycosep Column kit for aflatoxin to clean-up, and High-Performance Liquid Chromatography (HPLC) to detect the aflatoxins and determine the levels. Total aflatoxins were detected in the groundnuts, and they ranged between 0.36 ppb and 0.42 ppb. The levels of total aflatoxins were not beyond the regulatory standard of National Agency for Food and Drugs Administration and Control- NAFDAC (for ready to eat food, 4µg/kg while food that will still undergo processing 20µg/kg). Thus, the groundnut samples from the four markets are fit for consumption.

Thermal maturity evaluation on mildly artificially oxidised sporomorphs: A comprehensive calibration of palynomorph darkness index (PDI) with vitrinite reflectance

The assessment of thermal maturity of organic matter dispersed in sedimentary rocks is a fundamental task in geological studies, including the modelling of burial history of sedimentary basins, palaeotemperature evolution and the hydrocarbon generation assessment. Palynomorph Darkness Index (PDI) is a quantitative method for evaluating thermal maturity, based on the RGB image-analysis of palynomorphs. The growing use of this method has demonstrated the need for calibration against other maturity indicators such as vitrinite reflectance (Avg. VRo), Tmax, SCI (Spore Color Index) and TAI (Thermal Alteration Index). In the present study, PDI was determined on continental palynomorphs and compared with a large dataset of vitrinite reflectance measurements from the same samples, covering a thermal maturity range between the immature and overmature stages of hydrocarbon generation. The selected samples, belonging to twenty-five different wells, were previously oxidised with nitric acid (60%HNO3) for approximately 20 min to facilitate routine palynostratigraphic investigation. Calibration against vitrinite reflectance resulted in two linear correlation equations, one for Avg. VRo below 0.7% and another for values above 0.7%. Additionally, six samples from the Selli level of the Aptian Gorgo a Cerbara section (Umbria-Marche Apennine, Central Italy) were analysed to understand the differences in PDI values between artificially oxidised and unoxidised organic matter. The analysis showed a discrepancy of approximately 19% in PDI values for the same thermal maturity between unoxidised and oxidised sporomorphs. Our results confirm that PDI is a reliable and valid method for evaluating thermal maturity of organic matter, particularly when standard methods cannot be applied. Moreover, comparison with published data concerning other palynomorph groups (i.e., acritarchs) further supports the usefulness of this technique in geological investigations.

New colours for old in the blue-cheese fungus Penicillium roqueforti

Penicillium roqueforti is used worldwide in the production of blue-veined cheese. The blue-green colour derives from pigmented spores formed by fungal growth. Using a combination of bioinformatics, targeted gene deletions, and heterologous gene expression we discovered that pigment formation was due to a DHN-melanin biosynthesis pathway. Systematic deletion of pathway genes altered the arising spore colour, yielding white to yellow-green to red-pink-brown phenotypes, demonstrating the potential to generate new coloured strains. There was no consistent impact on mycophenolic acid production as a result of pathway interruption although levels of roquefortine C were altered in some deletants. Importantly, levels of methyl-ketones associated with blue-cheese flavour were not impacted. UV-induced colour mutants, allowed in food production, were then generated. A range of colours were obtained and certain phenotypes were successfully mapped to pathway gene mutations. Selected colour mutants were subsequently used in cheese production and generated expected new colourations with no elevated mycotoxins, offering the exciting prospect of use in future cheese manufacture.

Morphological and molecular characterization of the rust fungus, Phakopsora apoda causing leaf rust on Brachiaria grass in Rwanda

Brachiaria grass is one of the major forages that plays a key role in push pull technology. Different diseases including leaf rust caused by rust fungus, Phakopsora apoda have recently become an important challenge resulting in yield loss of Brachiaria grass in different countries including Rwanda. The objective of this study was to provide morphological and molecular characteristics of Phakopsora apoda causing Brachiaria leaf rust. Spores isolated from rusted Brachiaria leaves collected in five districts of Rwanda were analyzed. Samples were put in paper bags and left at room temperature for two days. Thereafter, spores were removed using brushes and put in eppendorf tubes, stored at 4oC in darkness for further characterization. For morphological characteristics, colour and measurements of spores were recorded using Optika B-350 microscope with installed camera and calibrated micrometer. Multigene analysis using rust specific primers and large subunit (LSU) of nuclear ribosomal RNA was performed for molecular characterization. The results indicated that the colour of spores was yellowish or brownish while the shape was ellipsoidal or circular with average measurements of 25.1µm and 16.8µm for length and width respectively. Primers amplified the size of DNA between 1291bp and 1381bp and the size between 874bp to 882bp for rust specific primers and LSU respectively. The identity of the sequence was 96% with e-value of 0, sequence coverage of 60% for rust primer and the sequence identity was 94.97% to 95.37%, sequence coverage of 99% to 100% and e-value of 0 for LSU primer. All sequences recovered from five isolates of leaf rust matched to the genebank accession number MG461668.1 for both rust specific and LSU sequences. The results of this study provide useful information to develop effective options for leaf rust disease management in Rwanda. Key words: Internal transcribed spacer, large subunit, nuclear ribosomal RNA, Phakopsora apoda, sequence, spore.

A study of the Effect of the Interaction Between the Secretions of the Roots of some Plants of the Cruciferous Family and the Biocontrol Factor Trichoderma spp. in Controlling fusarium wilt Disease on Okra Plants

This study surveyed, identified, and biologically controlled fusarium wilt on okra plants. The field survey found fusarium wilt on okra farms in Najaf, Diwaniyah, and Babylon. 18-73% were infected. Six Fusarium spp. isolates were found in wilted plants. Besides spore shapes and colours, the separated fungus differed in culture colour and growth rate. Fusarium spp. isolates also have different okra plant pathogenicities. However, isolate F2 (Abbasiya isolate) was the most harmful and adopted in following trials as the most virulent. The example isolate was PCR-diagnosed using rDNA-ITS marker. Fusarium solani. Thus, GenBank registered OQ729824. The effect of evaporated and non-evaporated compounds secreted from the tissues of cruciferous plants (Cabbage, broccoli, and cauliflower) on the culture medium P.S.A 1/4 showed that the compounds secreted from the roots of cabbage and broccoli inhibit and prevent the diagonal growth of the pathogenic fungus F. solani at an average rate of 0.00 cm compared to other treatments. Trichoderma spp. biological isolates tolerate cruciferous plant tissues better. The field experiment to assess the efficiency of the interaction between the root secretions of cruciferous family plants (Cabbage, broccoli and cauliflower) and okra plants in the presence of the bioagent factor T. longibrachiatum T2 showed a significant increase in okra plant growth and production. The interaction treatments between the roots of cabbage or broccoli plants in soil contaminated with the pathogenic fungus F. solani, with or without the biological fungus T2, completely protected the okra plants from disease during growth and harvest. Control treatment had 83.33% infection.

Spores Morphological Characteristics of Several Ophioglossaceae and Psilotaceae Fern in "Eka Karya" Botanical Garden - Bali

Ferns of Ophioglossaceae and Psilotaceae families can be found in the "Eka Karya" Botanical Garden, Bali as a collection or naturally growing in the botanical garden and those families are taxonomically classified as primitive ferns. The morphological characteristics of the family of Ophioglossaceae and Psilotaceae or even other types of ferns can be known through the morphological characteristics of the spores. This study aimed to characterize the spore morphology of the Ophioglossaceae and Psilotaceae fern of The "Eka Karya" Botanical Garden. Observation of the morphological characteristics of spores in the "Eka Karya" Botanical Garden was carried out by a simple method without acetolysis. The result of six types of fern plants from the family of Ophioglossaceae and Psilotaceae showed similarities to the spore unit, monads. Each family has unique characteristics that can be used to differentiate each other. The family Ophioglossaceae has a variety of spore colors, trilete spore types, mostly globose-shaped (except for one species the trilobate), the average polar diameter is 28.59±2.19 – 31.00±2.49 μm and the equatorial diameter is 32.85±1.74 – 37.55± 1.71 μm, the P/E ratio is 0.79-0.87, the shape based on the P/E ratio is suboblate, the spore size category is medium and has radial symmetry. For the family Psilotaceae, has a pale yellow-green spore color, monolete type, elongate-ellipsoidal shape, average polar diameter of 26.20±2.76 –29.81±2.96 μm and equatorial diameter of 52.98±2.55 – 63.31±4.65 μm, P/E ratio of 0.47-0.49, shape based on P/E ratio i.e. peroblate, large spore size category and has bilateral symmetry. Those characteristics are valuable taxonomic data that can be used as diagnostic characters for the identification of the families Ophioglossaceae and Psilotaceae.

Agaricus micromegethus, a new record for Turkish Mycobiota

The Agaricaceae is a monophyletic group of saprotrophic fungi distributed worldwide. The family exhibits considerable variations such as spore color and structure of pileus covering in morphology. Agaricus is the type genus of the family containing both edible and poisonous species, with more than 500 species worldwide. This genus includes many species that are considerably important so takes attention of scientists in the fields of medicine, biochemistry and food science. This study aims to introduce a new record, Agaricus micromegethus, for the Turkish mycobiota based on macro- and micromorphology. An illustrated description of the record is provided.

Impact of Thermal Maturation of the Upper Cretaceous Bituminous Limestone of Attarat Um Ghudran Central Jordan on Calcareous Nannofossil Preservation.

Oil shale deposits of the Late Cretaceous from three boreholes in central Jordan were examined to assess the impact of thermal maturation on the content of nannofossils. Thermal activity has been shown to have a strong effect on organic matter content and composition but its effect on calcareous nannofossil assemblages remains inconclusive. This study aims to determine the impact of thermal maturation on nannofossil assemblages and to compare this to an estimated maturity level based on bulk geochemical analysis. Micropaleontological and geochemical analyses were conducted on 31 samples from three oil shale wells drilled in Attarat Um Ghudran central Jordan. Several types of nannofossil preservation have been recorded, including dissolution, overgrowth, and breakage. In the Jordan oil shale sections, nannofossils exhibit a variety of preservation types, with intense dissolution in the middle part of the study sections. The vast majority of the samples had high TOC enrichment, with 29 samples exceeding values of >10%. Kerogen recovery and quality from the oil shale are very good, with a predominance of fluorescent amorphous organic matter (AOM) and minor algal components. The low fluorescence preservation index (FPI), which is 1 in most of the samples, indicates that alteration occurred due to intense thermal activities in the study interval. The palynomorph and AOM fluorescence, ranging from a spore coloration index (SCI) of 3 to 5, suggest that the studied samples were approaching the oil window. A correlation between the nannofossil preservation and geochemical parameters shows a predominance of poorly preserved nannofossils along with high total organic carbon contents and an elevated hydrogen index (HI). We show that low FPI values and a higher level of maturity are associated with poor nannofossil preservation, suggesting that nannofossils, in conjunction with petrographic analysis of kerogen, could be used as a rapid screening technique for estimating levels of oil-shale maturity. The nature of the tectonism in the study area, including faulting and a metamorphosed zone, enhanced the maturity, which might explain why the nannofossils were so significantly affected.

Source-rock evaluation of the Triassic – Jurassic interval of the Tanga Basin, coastal Tanzania

The Triassic-Jurassic interval is known to be the main source of oil and gas generation across the world. In the Tanga Basin of Tanzania, however, the potentiality of these strata for oil and gas generation has remained poorly understood. This study presents the organic geochemical analysis of the source rock within the Triassic-Jurassic interval of the Tanga Basin, integrating rock-eval pyrolysis, vitrinite reflectance and spore coloration analyses to assess the organic richness, quality and maturity for hydrocarbon generation. The results reveal that the Triassic and Jurassic shales are organically rich, with average total organic carbon (TOC) values of 1 wt % and 2 wt %, respectively. Triassic shales demonstrate the dominance of kerogen types II (oil), III (gas pone), II/III (gas with minor oil), and IV (inert) as indicated by hydrogen index values between 365 and 15 mg HC/g TOC. The hydrogen index (HI) values in the Jurassic interval range from 87 to 162 mg/HC/TOC, suggesting the dominance of kerogen type III (gas prone). Pyrolysis Tmax, vitrinite reflectance (Ro) and spore color index (SCI) indicate that the Triassic interval is thermally mature into a gas generation window, with average Tmax values of 450 °C, Ro ∼ 1.7% and SCI ∼8.5. The Jurassic interval is also revealed as thermally mature, with average values of Tmax ∼ 452 °C, Ro ∼ 0.7% and SCI ∼ 7.2, indicative of oil window. The positive findings of this study lay out an important foundation to follow up studies and extended exploration for hydrocarbon accumulations in the poorly explored Tanga Basin and across the coastal Tanzania in general.

Organic petrography and palynofacies of the Upper Cretaceous (Campanian-Maastrichtian) organic rich strata of the Quseir-Safaga Region, Eastern Egypt

The Campanian-Maastrichtian organic-rich rocks in the Quseir – Safaga Region in the Eastern Desert of Egypt have growing economic importance. This economic importance is discussed in many of previous studies by many of different geological tools that lacked the petrographic examination of organic matter occurrence modes. The organic petrography provides the essential tools for microscopic analysis to study the organic matter that are applied for the first time in the present study. The palynofacies and organic petrography are used in the present study to investigate the nature of the organic matter and the paleoenvironmental settings that controlled their distribution in the Duwi and Dakhla formations in the Younis and Mohamed Rabah areas (Egypt). The study of dinoflagellate cysts allowed the identification of the biostratigraphically characteristic assemblages of the Campanian – Maastrichtian in the Eastern Desert including Assemblage II/I (in Duwi Formation) and Assemblage III (in Dakhla Formation) that were identified in Egyptian oil shales of this time range. The identified assemblages are correlated with local and regional studies to delineating the formal biozonation. The organic matter in the Duwi Formation comprises rich fluorescent amorphous organic matter, prasinophytes, sporomorphs, dinocysts as well as a minor terrigenous component of phytoclasts. In the Dakhla Formation, the fluorescent AOM is found to be highly mixed with Botryococcus in addition to prasinophytes and marine palynomorphs. The paleoenvironmental analysis indicates deposition in distal anoxic to proximal suboxic marine conditions with high paleoproductivity. The results are confirmed with the inorganic geochemical composition of redox sensitive elements. The analysis reveals that the Younis section is differentiated into two palynofacies types (proximal, suboxic high productivity in the Duwi Formation and distal anoxic in the Dakhla Formation). The Mohamed Rabah section, one palynofacies type is recognized that is proximal, suboxic high productivity. The principal component analysis is used to interpret the distribution of organic matter abundances. The kerogen types are distinguished based on the area percentages of the fluorescent organic matter and application of kerogen plots. The samples of both formations fall within oil prone kerogen type II. The spore coloration and measured vitrinite reflectance indicate immature kerogen in the studied sections. The organic matter in the studied rocks comprises hydrogen rich compounds that can be treated for direct composition or retorted to extract shale oil. The heavy metals concentrations are significant and present technology will increase its economic value.

Rhizophagus irregularis, the model fungus in arbuscular mycorrhiza research, forms dimorphic spores.

Rhizophagus irregularis is the model species for arbuscular mycorrhizal fungi (AMF) research and the most widely propagated species for commercial plant biostimulants. Using asymbiotic and symbiotic cultivation systems initiated from single spores, advanced microscopy, Sanger sequencing of the glomalin gene, and PacBio sequencing of the partial 45S rRNA gene, we show that four strains of R. irregularis produce spores of two distinct morphotypes, one corresponding to the morphotype described in the R. irregularis protologue and the other having the phenotype of R. fasciculatus. The two spore morphs are easily distinguished by spore colour, thickness of the subtending hypha, thickness of the second wall layer, lamination of the innermost layer, and the dextrinoid reaction of the two outer spore wall layers to Melzer's reagent. The glomalin gene of the two spore morphs is identical and that of the PacBio sequences of the partial SSU-ITS-LSU region (2780 bp) obtained from single spores of the R. cf fasciculatus morphotype has a median pairwise similarity of 99.8% (SD = 0.005%) to the rDNA ribotypes of R. irregularis DAOM 197198. Based on these results, we conclude that the model AMF species R. irregularis is dimorphic, which has caused taxonomic confusion in culture collections and possibly in AMF research.

Palynofacies analysis of the JOG16N-8 borehole, K5 formation from the Maniamba Basin (middle Permian), Mozambique: A contribution for hydrocarbon exploration

The Maniamba Basin in Mozambique is surveyed mainly in regard to coal exploration. However, this basin is also known for containing well preserved fossil plants and vertebrate fossils that shed light to the understanding of Gondwana ecosystems. Nevertheless, organic matter analysis (palynofacies) and its implication for depositional environment and hydrocarbon source rock have not yet been performed. Here, we report for the first time in the Maniamba Basin, results from palynofacies analysis combined with thermal maturation and kerogen typification. Palynofacies analysis was applied on 69 samples from the sediments of the JOGN16N-8 borehole, K5 Formation (middle Permian).The results indicate that sediments are dominated by phytoclasts with less abundant sporomorphs and sparse amorphous organic matter (AOM). Three palynofacies were identified suggesting depositional settings in a general proximal and oxic lacustrine-fluvial deltaic environment. The dominance of opaque phytoclasts may be due to wildfires, oxidation conditions before or post deposition in proximity to terrestrial settings and an environment under obliquity cycle controlled monsoon climate. The organic matter composition combined with Spore Colour Index (SCI), pointed out the existence of an abundant type IV kerogen followed by type III in immature phase suggesting very little or no potential for gas exploration. Very few horizons suggest the existence of kerogen type II. This study, gives significant information for better understanding of the variation of organic matter, palaeoenvironment and source rock potential of the studied area.

Biosynthesis and characterization of chitosan nanoparticles, determination of its antifungal and antiaflatoxigenic against Aspergillus flavus isolates

Aflatoxin is a mycotoxin generated mostly by the fungus Aspergillus flavus, which may be found in food and feed. It is a carcinogenic poison for both humans and animals. The goal of this investigation was to see if toxicogenic A. flavus strains might be found on nuts in the Kurdistan Region. A total of Fifty nut samples. The colony color of A. flavus and texture were used to identify macromorphological qualities, whereas the spore color, size, structure, conidiophore structure, and vesicle shape were used to assess micromorphological properties. Direct imaging of the UV fluorescence of A. flavus colonies on coconut agar media (CAM) was used to detect aflatoxin formation. Natural compounds, such as chitosan, have been suggested as a way to prevent fungal infection because of their extensive and well-known antibacterial action against a variety of microorganisms. The goal of this entry was to morphologically characterize and determine aflatoxigenic A. flavus isolates, characterize nanoparticles using UV–visible, X-ray diffraction (XRD), Energy-dispersive X-ray (EDX), and scanning electron microscope (SEM) analyses, and determine the formulations' in vitro antifungal activity on the treated fungus. Individual concentrations were created by altering the percentages of ingredients such chitosan solution, chitosan nanoparticles, glycerol, and canola oil. The final concentrations of chitosan solution and chitosan nanoparticles were 20% and 2% respectively. Chitosan nanoparticles completely inhibit the growth of A. flavus at 2%.

Morpho-molecular variability of different isolates of Ustilagonoidea virens causing false smut of rice

Spore balls of false smut of rice caused by Ustilagonoidea virens were collected from different major rice belts of eastern part of India. Ten isolates from ten different locations were collected and isolated in the laboratory for their, cultural, morphological and molecular characterization. Potato sucrose agar media was used for their cultural studies and observation on colony diameter, colour and sporulation were made. Spores of all the isolates were observed under scanning electron microscope (SEM) and light microscope for spore size, spine length and colour. Differences in colony characters were observed where the highest mycelial growth was observed in isolate Uv2 with 5.33 cm colony diameter and lowest mycelial growth was observed in Uv9 (3.70 cm). Most of the isolates produced white and circular colony. Spores of all the isolates observed under a light microscope appeared to be olive green in colour, however, a significant variation in spore size and spike length under SEM was observed. Spores size and spike length of different isolates ranged between 4.533 μm to 6.169 μm and 362.567 nm to 799.533 nm, respectively. For genetic identification and variability, DNAs of isolates were amplified using ITS1 and ITS 4 primers. The length of nucleotide sequences of different isolates varied from 583 to 606 bp. Phylogenetic analysis revealed genetic variation among the isolates, dividing them into two major groups.

Characterization and Determination of Aflatoxigenic and Non-aflatoxigenic Aspergillus flavus Isolated from Bakery Food Products from Frontier around Davangere District

Mycotoxins are secondary metabolites produced by filamentous fungi in food and feed due to several conditions that affect fungal growth and mycotoxin production in different ways. Mycotoxin contamination in bakery food products is seriously dangerous to humans and animals. This study aimed to morphologically characterize and determine the aflatoxigenic and non-aflatoxigenic Aspergillus flavus isolates. Thirty three isolates of A.flavus were obtained from bakery food products collected from bakeries in rural areas like Bathi, Kodaganur, Bada, sasalu, Mayakonda, Avargere, Anaberu, Alur, Attigere, Echagatta around Davangere city. They were cultured on Potato Dextrose Agar medium (PDA), Rose Bengal Agar medium (RBA), Czapec(dox) agar medium (CZA) and Sabouraud’s dextrose agar medium (SDA). By observing the colony color and texture macromorphological characteristics were determined and micromorphological characteristics were determined by observing the spore color, size, structure, conidiophore structure, conidia, vesical shape under microscope. The production of aflatoxin was determined by UV fluorescence of isolates on coconut cream agar (CCA) medium plates. In aflatoxin detection 20 (60.60%) isolates of A.flavus shows positive results and 13 (39.39%) isolates of A.flavus shows negative results. The highest incidence of A.flavus was recorded in samples collected from Attigere followed by Bathi, Alur, Echagatta, Kodaganur, Bada, Anaberu, Sasalu, Mayakonda, Avargere. The incidence of A.flavus that produces aflatoxin highlights the necessity of taking action to eliminate their presence in food. The non-aflatoxigenic strains are being used in a biological control strategy to outcompete the aflatoxigenic ones.