Abstract Globba pendula Roxb. is a species in Zingiberaceae with prospective source of novel bioactive compounds. Traditionally, the roots or rhizomes have been used to treat several ailments in South Sumatra, Indonesia. Bioprospecting of its bioactive compounds is still limited along with its associated microorganisms, especially the natives one in North Sumatera. In this study, we conducted a preliminary screening of 16 (sixteen) fungal endophytic isolated from rhizome of G.pendula in Taman Hutan Raya, North Sumatera. The isolates were subjected against Staphylococcus aureus ATCC® 29213™ using dual culture plate assay. The sixteen isolates were differentiated morphologically by considering characters such as: Form, Elevation, Margin, Color, Texture, Concentric ring and Radial lines. All isolates were antagonists of S.aureus with different performances. Two isolates exhibited very strong antagonistic activity (++++), 13 isolates with strong activity (+++), and only one with mild activity (++). The results suggest that fungal endophytes from G. pendula may be used as source of antimicrobial compounds. The molecular identification of endophytes is currently under investigation.
Lignocellulose is a core component of plant biomass and the most abundant carbohydrate polymer in nature. It is cheap and renewable and has several potential applications; however, it remains underutilized because of its recalcitrance to degradation. Cellulolytic microbes have been found in the gut of herbivorous insects, such as grasshoppers. This study aimed to isolate lignocellulolytic bacteria from the gut of grasshoppers (Oxya chinensis) and determine their diversity and potential biomass-degrading activity. A total of 27 culturable isolates were obtained from the grasshopper foregut, midgut, and hindgut. The bacteria hydrolyzed cellulose and lignin, as indicated by a cellulolytic index of 0.12–1.23 and ligninolytic index of 0.1–1.47. Five potential cellulolytic bacterial isolates were selected. Based on 16S rRNA sequencing, the isolates were identified as Bacillus wiedmannii (foregut), Bacillus marcorestinctum, Bacillus halotolerans (midgut), Paenibacillus zanthoxyli, and Bacillus hominis (hindgut). The highest specific cellulolytic activity (0.0068 U/mg) was detected in B. wiedmannii (OCF2), which could be exploited as a potential source of cellulases.
Abstract The rhizosphere has been known to contain rich microbial community which is directly influenced by secretions of roots. Rhizosphere microbes are known to have various benefits such as protection of plant from pathogens and toxic compounds, producing plant growth hormone, nitrogen fixation, and solubilizing phosphate. The objective of this study was to obtain rhizosphere bacteria capable of inhibiting the growth Fusarium oxysporum which is common pathogen attaching Capsicum annum. Bacteria were isolated from rhizosphere C. annum of local farm in Kabanjahe North Sumatra. Nine isolates based on morphological performance and biochemical analyses were obtained. Antagonistic test showed that two isolates BR6 and BR9 inhibited the growth of F. oxysporum with inhibition rate of 60% and 52%, respectively after 7 days incubation. These isolates also exhibited the activity to solubilize phosphate in Pikovskaya media with solubility index of 3.04 and 2.77, respectively. The other isolate BR5 even showed higher phosphate solubility index (3.42). These results suggest these isolates may have important role to support the growth of C. annum by providing protection from pathogens and phosphate ion. Then, study on the control of F. oxysporum attack on C. annum seedlings using these potential isolates is in process in our laboratory, as well as their molecular identification based on 16S rRNA.
The emergence of bacterial infections caused by resistant strains poses a threat to the development of new antibiotics. The majority of antibiotics being produced has been accelerated through the finding of newly reported natural products, especially those originated and produced by biological sources. Endophytic fungi residing in medicinal plants may be regarded as potential sources and encourage the exploration of more plant species for their antimicrobial activity. Our current study reports on the assemblage of endophytic fungi that colonize the rhizomes, using Globba patens a representative of Zingiberaceous species from North Sumatra. Twenty-six fungal morphotypes were obtained and differentiated by their morphological features. Each isolate was tested against human pathogenic bacteria namely Staphylococcus aureus ATCC® 29213™, Methicillin-resistant S. aureus (MRSA) ATCC® 43300™, Escherichia coli ATCC® 25922™, and Enteropathogenic E. coli (EPEC) K11 in a dual culture assay. The results revealed that the majority of fungal isolates were strong antagonists against S. aureus and E. coli but not against MRSA and EPEC. Isolate Gp07 was the most potential fungus with a wide range of antibacterial activities and was subjected to further species-level identification based on its morphological characteristics and DNA sequence in the ITS-rDNA region. The isolate Gp07 was identified as Colletotrichum siamense, yet the presence of C. siamense in the rhizome of G. patens is not fully understood while possibly being characterized as the antibiotics-producing agent in the future.
Oil palm plantations (OPPs) have initiated in Indonesia at the Dutch colonial era. After the reformation era, the OPPs continued to extend widely including in South Tapanuli. However, it is suspected that the expansion of new OPPs by converting natural forests. This study aimed to assess the distribution and extension of OPPs in South Tapanuli using remote sensing (RS) and geographic information system (GIS). Land cover classification was obtained by using supervised classification with maximum likelihood approach in Landsat images of 1989, 1998, 2007 and 2019. The research showed that the OPPs in South Tapanuli have increased nearly 2.5 times in the last three decades that was from 7.56% in 1989 to 18.79% in 2019. This study indicated that some portion of new OPPs by converting natural forests, including in conservation as well as protection forests. This practice is expected to cause disruption of harmony in nature and the human environment, such as increased flooding during rainy season, drought during dry season, landslide as well as human-wildlife conflict. Therefore, land use must be a concern in developing new oil palm plantations in the future. Subsequently, it needs simultaneously to handle the OPPs have been planted on land that is not intended.
Abstract Medicinal plant from members of Zingiberaceae have been used as traditional remedies by marginal communities. To date, information and potential of these endophytes, especially endophytic fungi is still limited to certain taxa and properties. The present study investigates one of plant growth promoting properties possessed by endophytic fungi, which is the ability to produce extracellular Indole-3-acetic acid (IAA). Rhizome of Alpinia sp. sampled from Hutan Sibayak, North Sumatera was used as source of isolation of endophytic fungi. The endophytic fungal isolates were grown in Czapek-dox broth supplemented with 0.1% (w/v) L-tryptophan for 7 days to induce secretion of extracellular IAA. IAA concentration was measured colorimetrically using Salkowsky’s solution by comparing absorbance (A 530 ) of standard pure IAA with culture filtrates from each isolates. The study obtained 5 endophytic fungal isolates from Alpinia sp. rhizome differentiated morphologically. The highest IAA content in culture filtrate (42.91±1.41 μg.mL −1 ) was produced by isolate Al04SU followed with Al02SU, Al05SU and Al01SU with IAA concentration of 26.25, 19.55 and 17.26 μg.mL −1 , respectively. Molecular identification of isolate Al04 based on ITS-DNA similarity showed that isolate was closely related to Aspergillus flavus and confirmed through phylogenetic tree construction. The presence of IAA-producing endophytic fungi from Alpinia indicates that medicinal plant may harbor bioprospective strains which could be used in crop improvement with further and deeper investigation.
The aim of this study is to analyze the influence of the role of youth on agricultural development in the Gayo Lues Regency of Aceh Province. The research was conducted by survey method, the sample was determined by simple random sampling and the number of samples was determined by the Frank Lynk formula. This research is explanatory which explains the relationship between the variables studied. Data analysis was performed with descriptive analysis and multiple linear regressions. The results of the research show that the role of youth as agent of change, agent of development and agent of modernization has a mean score of 3.57 in the interval 3 F table and P value t table and P value <0.05 shows the role of youth as agents of change, agent of development and agent of modernization partially have a significant positive effect on agricultural development. So it can be concluded that there is an influence of the role of youth on agricultural development in the Gayo Lues Regency of Aceh Province.
Abstract Endophytic microorganisms are microbial associates living in various part of host, yet expressing benefits to healthy plants. Existence of species-specific endophytes, endophytic fungi is still poorly studied especially in Zingiberaceae. In this study, we reported several endophytic fungal species isolated from rhizome of Elettaria through isolative efforts and molecular evidence. Host plant, Elettaria sp. was sampled from representative natural area, i.e. Hutan Sibayak which is known as biodiversity spot for Zingiberaceae in North Sumatera. Molecular identification revealed the identity of five isolated fungal strains collected from rhizomes of Elettaria , namely Trichoderma atroviride, Curvularia lunata, Schizophyllum commune, Trichoderma harzianum and Pholiota multicingulata . Phylogenetic tree is constructed based on Neighbor-joining method in a bootstrap test (1000x replication) with outgroup and database retrieved from NCBI GenBank. From our perspective, this is the first report on finding fungal endophytes from rhizomes of Elettaria sp. yet further investigation is needed to evaluate their future bioprospectives.
