No abstract

The role of tropical forests for maintaining environmental functions is decreasing due to the rapid changes to agricultural purposes. Agroforestry system is assumed to be an alternative system which reduces the negative impact of the conversion in term of maintaining the level of soil macrofauna diversity. This study was conducted at UB Forest within the period November 2017 to February 2018 by collecting soil macrofauna from 9 different land use types using hand sorting along with pitfall sampling for comparison. ANOVA and various diversity indexes were used (Shannon index, Pielu index, etc) to determine macrofauna structure and communities. Total soil C was examined using Walkley and Black method along with Particulate Organic Matter (POM) C fractionation approaches. Litter inputs were collected using a litter trap method, while in-situ litter were determined using destructive methods. Biplot and CVA multivariate analyses were adopted to determine the impact of different management on soil macrofauna diversity and structure. The result showed that conversion to agriculture practices reduced the structure, population and abundance of soil macrofauna as litter production, organic matter and soil C content decreased. The lowest abundance of individual soil macrofauna at monoculture system (PM) was reduced to 45 morphospecies compared to pine coffee agroforestry at the age of 4 (PK4:20 years after planting) system as much as 104 morphospecies. There was a strong relationship between litter thickness and the abundance of soil macrofauna. Both methods (Hand sorting vs Pitfalls traps), had a different ability for collecting soil macrofauna communities. Species occurs at rich or low organic matter input can be adopted as soil macrofauna bioindicator of changes on an ecosystem. Biplot and CVA methods can be used to distinguish and to cluster the impact of different management at various agroforestry systems.

The sugarcane leaf litter contains organic material and if it is returned to the soil, it will increase the diversity of Collembola. Collembola has an important role as a decomposer of soil organic matter and bioindicator of soil health. This study was conducted to determine the effect of sugarcane leaf litter on the diversity of Collembolan in sugarcane plantation at Kebonagung Sugar Factory, Malang. This study was conducted from March to June 2018. Transect method was used in sampling method. The pitfall traps were used to obtain Collembolan samples on the surface of the ground while the Berlese-Tullgren funnels were used to obtain Collembolan samples inside the soil. A total of 5,535 collembolan were collected. Five species were collected, including Brachystomella sp., Folsomides sp., Mesaphorura sp., Alloscopus sp., and Dicranocentrus sp. Applying sugarcane leaf litter to the soil has a positive effect on Collembolan diversity, as evidenced by the increasing value of diversity index on the soil surface from 0.53 to 1.11 and decreasing the value of dominance index on the soil surface from 0.76 to 0.43.

Cordyceps militaris is one of entomopathogenic fungi species that is well known to be a traditional medicine in China for decades. Although the pharmaceutical and/or toxic properties of C. militaris has attracted attention as a promising resource for finding bioactive compounds, only a few substances including cordycepin have been reported so far. In the previous report heterologous expression of LaeA, a global regulator for secondary metabolites production in fungi, has been succeeded in C. militaris. The LaeA-engineered transformants are proved to produce new and/or elevated production of secondary metabolites, as detected by HPLC analysis. In order to further characterize the secondary metabolites that were being significantly produced by LaeA transformant, HPLC profiling and structure elucidation by proton NMR were conducted in two target compounds, designated as compound 1 and compound 2. Compound 1 possessed the highly similar characters to insect toxin beauvericin in UV spectrum, molecular weight, and retention time in HPLC analysis. Proton NMR analysis revealed that compound 1 had the same proton signals as beauvericin.

The current study aims to perform microencapsulation of R. tuberosa L. extracts using chitosan crosslinked to sodium tripolyphosphate (NaTPP) as wall materials by spray drying and to analyze their in vitro biological activities. The influence of manufacturing conditions, like pH, chitosan concentration, and stirrer time, was assessed. Results showed that microcapsules prepared in pH 4 with a concentration of 0.1% (w/v) chitosan, and 90 min stirring time had 51.80% encapsulation efficiency and high in vitro biological activity. These were shown by high in vitro alpha amylase inhibition and antioxidant activity with IC50 values of 50.65 μg/mL and 123.97 μg/mL, respectively. Releases of the bioactive compounds in microcapsules of R. tuberosa L. were carried out on phosphate buffer medium pH 2.2 and pH 7.4 with times release of 30, 60, 90, and 120 min. The bioactive compounds were released in pH 2.2 in 120 min at 2.48%. At pH 7.4, the active ingredients were more easily released, by 79.90% in 120 min. The microcapsules’ morphology showed a rough surface with spherical forms and the average sizes were 53.41 μm. This study supports the essential role of microencapsulation in improving plant extracts with reserved biological activities.