Microvirga Puerhi Sp. Nov., Isolated from Puerh Tea Garden Soil

Strain WGZ8T was isolated from a soil sample of Puerh tea garden in Puer city, Southwest China. The isolate was rod-shaped, Gram-stain negative, aerobic, non-motile. Growth occurred within 0-3.0% (w/v) NaCl (optimal concentration, 0-1.0%), pH 5.0-11.0 (optimal pH, 7.0) and 10-40°C (optimal temperature, 28°C). 16S rRNA gene sequences based phylogenetic and phylogenomic analysis revealed that WGZ8T belonged to the genus Microvirga. Its major cellular fatty acids were C19:0 cyclo ω8c, C16:0, C18:1ω7c and/or C18:1ω6c. The profile of polar lipids included phosphatidyldimethylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylcholine, diphosphatidylglycerol and phosphatidyl-glycerol. The only respiratory quinone was detected as ubiquinone 10 (Q-10). The genome size of strain WGZ8T was 5.17MB, and the content of DNA G+C was 61%. Based on the results of digital DNA-DNA hybridization and phenotypic results, strain WGZ8T could be concluded as a novel species of the genus Microvirga, for which the name Microvirga puerhi sp. nov. is proposed. The type strain is WGZ8T (=CGMCC 1.19171T=JCM XXXXT).

Isolation and characterization of nitrogen-fixing bacteria from soil sample in Dhaka, Bangladesh

Biological nitrogen (N2) fixation is very essential for limiting the growth of plants and agricultural crops. The present study was conducted to potentially isolate N2-fixing bacteria from garden soil sample at Stamford University Bangladesh, Siddeswari, Dhaka. Here, we used culture-dependent method to perform this experiment. Firstly, we collected garden soil sample, diluted and inoculated in N2-free Jensen’s media by maintaining the aseptic procedure. We obtained 5 different colonies from soil samples. We cultured the isolates in N2-free Jensen’s media containing bromothymol blue (BMB) and also, in Yeast Extract Mannitol Agar (YEMA) media containing congo red to confirm nitrogen fixation capacity. We collected the colony characteristics of all the isolates. Only 1A isolate showed good growth after 24 h of incubation among all the isolates. We performed ammonification test with Nessler reagent to confirm N2-fixing ability for our selected isolates. The 1A isolate was positive in ammonification test. Culture, microscopy and biochemical tests were performed to identify isolate 1A. This isolate was presumptively identified as Azotobacter sp. In the present study, Azotobacter sp. that was isolated from the soil sample was found to be a potential N2-fixing bacterium. Isolate 1A can be used for N2-fixation to boost production of crops. Stamford Journal of Microbiology, Vol.11 (1) 2021: 11-13

Growth Response of Abaca (Musa textilis Nee) in Abandoned Mine Soil Amended with Oil Palm Residues

The mining industry is one of the leading sectors providing economic benefit to the community. However, mining minerals inevitably affect the ecosystem function of the land, thereby reducing ecological services provided to mankind. Soil remediation is done to restore ecological integrity while mitigating degradation processes. Thus, this study was conducted to determine the chemical properties of abandoned mine soil and to determine the effects of oil palm residues on the growth performance of abaca (Hybrid 7) grown in mined soil under nursery conditions. This study was arranged in a completely randomized design (CRD) with five treatments and four replications, namely, T1 - Mined Soil Alone, T2 - Garden Soil Alone, T3 - Mined soil + Oil Palm Sludge, T4 - Mined Soil + Oil Palm Empty Fruit Bunch (EFB) Biochar, T5 – Mined Soil + Oil Palm Vermicast. Chemical analysis of mined soil revealed extreme acidic soil condition, low organic matter, CEC, N, K, and high P content relative to soil nutrient sufficiency criteria. Mined soil contained 0.347 mg/kg Cd and 0.230 mg/kg Pb which are within the tolerable limit of 2.00 mg/ kg for Cd and 300 mg/kg (Pb), respectively. Application of oil palm residues in mined soil can significantly improve the morphology and dry matter yield performance of hybrid 7 abaca seedlings. Plants grown in mined soil amended with oil palm residues were taller, larger pseudostem girth with more and bigger functional leaves, and had a higher survival rate compared to those grown in soil derived from the abandoned mining area. Abaca plants grown with amendments had accumulated higher dry matter. Oil palm residues particularly vermicast has greater potential as soil amendment under degraded mined in Mawab, Davao de Oro.

Germination of Balsa Seedlings (Ochroma lagopus Swartz) under Different Sowing Media in East New Britain, Papua New Guinea

A good sowing media ensures better anchorage of plants, provides a reservoir of nutrients and water, and enhance gaseous exchange with the atmosphere. Balsa (Ochroma lagopus Swartz); Vimmy variety, has proven its versatility in producing some of the best phenotypic characteristics such as higher jorquette height, less branching and high log volumes. This experiment was carried out using a combination of three different local materials; local garden soil, pumice soil and sawdust but in different combination ratios aimed to investigate the best combinations. Six treatments were tested: T1= Pure Garden soil, T2= Pumice, T3= Control (75% large coarse sawdust, 25% pure garden soil), T4= Pure Sawdust, T5= 50% medium coarse sawdust, 50% pure soil, and, T6= 33% medium coarse sawdust, 33% Pumice, 33% Pure garden Soil. The daily average germination count in Treatment 5 (50% medium coarse sawdust & 50% pure soil) produced constant germinations from day fifteen (15) to day twenty one (21). Treatments 1, 2, 3, 4 and 6 showed high variations in their daily average germination for the same period but did not produce a constant supply of germinations. Treatment 5 had the highest emergence rate index (ERI=71.76) followed by treatment 1 (ERI=66.59). Treatment 4 had the third highest seedling emergence (ERI=63.74) followed by treatment 3 (ERI=59.37), treatment 6 (ERI=57.22) and treatment 2 (ERI=53.81) at the lowest continuum. Substrates containing 50% soil and 50% medium coarse sawdust are regarded as better sowing media for O. lagopus seedlings.

A Consolidated Method for Selective Isolation of Actinomycetes Based on Choice of Substrate

Actinomycetes are known as filamentous, Gram positive bacteria. They form the majority of the microbial load in various niches; soils, composts, etc. The study aimed to evaluate the method of isolating slow growing actinomycetes from four different sources: garden soil, cow dung manure compost, floral waste compost, and floral waste vermicompost. In this study, an integrated method consisting of physical and chemical pretreatment of the sample and the use of selective media was used to isolate actinomycetes. Physical treatment includes air drying, sun drying, dry heating in an oven, and moist heat treatment, whereas chemical treatment includes enrichment of the sample with CaCO3 followed by plating on actinomycetes-specific media with the incorporation of antibacterial and antifungal antibiotics. The actinomycetes count on the plate was reported in CFU/gm of dry wt. Morphological and microscopic characteristics of purified isolates were noted. The results were compared, and it was found that the pretreatment method of a particular sample depends on the choice of substrate. Overall, physical treatment followed by chemical enrichment showed relatively higher counts on the plate and better results. Here we also found the dominance of fluorescent Pseudomonas sp. in case samples from vermicompost. The study can be of great importance in isolating novel and rare genera of actinomycetes. These methods can help speed up the isolation and screening of novel actinomycetes which will ultimately be important for the discovery of antibiotics and other industrially vital bioactive compounds.

Substrate-Dependent Effect of Vermicompost on Yield and Physiological Indices of Container-Grown Dracocephalum moldavica Plants

The development of sustainable plant production systems involves a search for different alternatives to chemical fertilizers. The aim of the present study is to compare growth and physiological effects of vermicompost on Dracocephalum moldavica plants in controlled conditions, using two types of commercially available substrates. The intention is to determine whether nondestructively measured photosynthesis-related parameters are useful for monitoring the physiological status of plants. The plants were cultivated in two base substrates without or with the addition of mineral fertilizer, as well as an amendment with vermicompost at a 20% or 30% rate in the conditions of an automated greenhouse. The biomass accumulation for control plants of D. moldavica was identical in peat substrate and commercial garden soil. The average growth increase by mineral fertilizer was 25% for D. moldavica plants grown in peat and 15% for plants grown in soil. Substrate amendment with 20% vermicompost resulted in an 114% average increase in biomass for plants grown in peat and a 98% average increase for plants grown in soil, but for plants at 30% the amendment rate increase was 148% and 68%, for peat and soil, respectively. Consequently, the addition of an identical amount of vermicompost resulted in a poorer growth response of plants in commercial garden soil as a substrate in comparison to peat, but an increase in the amendment rate from 20% to 30% resulted in some growth inhibition for these plants. Chlorophyll concentration was positively affected by the vermicompost amendment in a concentration-dependent manner, but this effect during a cultivation period appeared relatively late. Large differences were found between the three groups of fluorescence-derived parameters, with variable levels of predictability with respect to the differences in plant yield due to the pronounced variation in correlation through time. It is concluded that the incorporation of vermicompost for the cultivation of D. moldavica, even in substrate mixes with relatively high and balanced composition of plant-available nutrients, benefits plant growth, physiological status and biomass yield, but it is necessary to explore interactions between vermicompost and other substrates leading to possible changes in quality-related characteristics of vermicompost in substrate mixes.

Multi-layer Budding of Oversized Rubber (Hevea brasiliences) Seedlings: Success and Growth in Different Soil Media

The study on Multi-layer budding of oversized rubber seedling aimed at evaluating the success of multiple budding operation on single seedling of rubber tree species comprising of 4 to 7 budding layers per seedling. The experiment used randomized complete blocked design layout with 3 treatments such as 4, 5 and 7 layer budding in a single seedling replicated 4 times. Results revealed that the highest number of budding layers succeeded significantly higher as compared to 4 and 5 layers. The main survival percentage is about 79.17% for the 7 layers, 76.52% for the 5 layers and only about 55.36% for the 4 layers. Pure garden soil reported to have significant results on sprouting rate, sprout length, stalk diameter and number of leaves. This finding emphasized that budding of rejected oversized rubber seedlings grown in an abandoned nurseries can be reutilized for mass production of budded cuttings through multiple budding of 7 layers per seedlings to maximize planting materials derived from single seedlings.

In-vitro propagation and phytochemical profiling of a highly medicinal and endemic plant species of the Himalayan region (Saussurea costus)

Efficient protocols for callus induction and micro propagation of Saussurea costus (Falc.) Lipsch were developed and phytochemical diversity of wild and in-vitro propagated material was investigated. Brown and red compact callus was formed with frequency of 80–95%, 78–90%, 70–95% and 65–80% from seeds, leaf, petiole and root explants, respectively. MS media supplemented with BAP (2.0 mgL−1), NAA (1.0 mgL−1) and GA3 (0.25 mgL−1) best suited for multiple shoot buds initiation (82%), while maximum shoot length was formed on media with BAP (1.5 mgL−1), NAA (0.25 mgL−1) and Kinetin (0.5 mgL−1). Full strength media with IAA (0.5 mgL−1) along with IBA (0.5 mgL−1) resulted in early roots initiation. Similarly, maximum rooting (87.57%) and lateral roots formation (up to 6.76) was recorded on full strength media supplemented with BAP (0.5 mgL−1), IAA (0.5 mgL−1) and IBA (0.5 mgL−1). Survival rate of acclimatized plantlets in autoclaved garden soil, farmyard soil, and sand (2:1:1) was 87%. Phytochemical analysis revealed variations in biochemical contents i.e. maximum sugar (808.32 µM/ml), proline (48.14 mg/g), ascorbic acid (373.801 mM/g) and phenolic compounds (642.72 mgL−1) were recorded from callus cultured on different stress media. Nonetheless, highest flavenoids (59.892 mg/g) and anthocyanin contents (32.39 mg/kg) were observed in in-vitro propagated plants. GC–MS analysis of the callus ethyl acetate extracts revealed 24 different phytochemicals. The variability in secondary metabolites of both wild and propagated plants/callus is reported for the first time for this species. This study may provide a baseline for the conservation and sustainable utilization of S. costus with implications for isolation of unique and pharmacologically active compounds from callus or regenerated plantlets.

Identification and Analysis of Plant Growth Promoting Bacteria in LEAF Community Garden Soil

In today’s largely populated modern world, crop yield is becoming increasingly important. To increase crop yield, new modern technologies for farming are continuously being innovated. The aim of this study is the identification of Plant Growth Promoting Bacteria (PGPBs) and their properties. In order to conduct the experiment, soil samples were collected from the community garden LEAF (Local Ecology and Agriculture Fremont). These samples were grown in Luria Bertani agar plates, and the two bacterial strains that grew from them were analyzed to determine the species of the bacteria. Using a DNA extraction kit, DNA was extracted from the bacteria and then amplified versions were sent to RF Biotech for DNA sequencing. The DNA sequences were then used to determine that the two bacterial species in question are Bacillus cereus and Morganella morganii. Afterwards, multiple assays were used to measure the efficiency of each bacterial species to absorb various substances that would be helpful for plant growth. The aim of this research is to better understand which bacterial strains are beneficial for plants, and which are harmful. Through having greater zones of inhibition, the bacterial species M. morganii proved to be more efficient in the siderophore and phosphate solubilization assays. In contrast, the bacterial species B. cereus proved to be more efficient in the cellulase and amylase production assays. These results will assist LEAF in enriching their soil in order to increase their crop yields by creating an increase in concentration of advantageous bacteria and decrease that of detrimental bacteria.

Effects of Plastic Pollution of Soil on the Growth and Survival of Bacteria and Fungi

The study examined the effect of plastic waste on soil bacteria and fungi. The test soil samples were collected from Lokoja international market waste dump site and the control soil sample was collected from non plastic contaminated garden in Salem University, Lokoja. The samples were analysed using Gas chromatography with mass spectrometer. The test soil sample soil sample had high quantity of plastic contaminant which were Methylene chloride 17.45mg/kg, hexane 10.05mg/kg, chloroform 1.56mg/kg, toluene 5.87mg/kg, tetrachloroethylene 1.48mg/kg as compared to the control garden soil sample, which had methylene chloride 0.54mg/kg, hexane 0.26mg/kg, chloroform 0.31mg/kg, toluene 5.87mg/kg and tetrachloroethylene 0.01mg/kg. The result showed the presence of plastic in the soil and it effect on bacteria and fungi. The totals of 11 bacteria were isolated from both soil samples using nutrient agar. The bacteria isolated are; Corynebacterium spp. (12%), Enterobacter spp. (8%), Acinetobacter spp. (6%), Escherichia coli (16%), Epidermis, Bacillus subtilis (15%), Serratia sp. (8%), Proteus spp. (4%), Micrococcus luteus (7%), Flavobacterium spp. (10%), Pseudomonas aeruginosa (15%). Micrococcus luteus, Flavobacterium spp. and Pseudomonas aeruginose were not isolated in plastic composted soil sample due to the presence of plasticizers. The total of 6 fungi were isolated, namely Penicilliun expansion (12%), Sacchromyces sp. (24%), Aspergillus niger (19%), Fusarium spp. (20%), Rhizopus stolonifer (10%) and Mucor piriformis (15%). This study reveals the effect of plastic waste, as it inhibits the growth of microorganism that is important for soil activities, thereby reducing the soil nutrients, fertility and productivity.