Secondary metabolites are compounds produced by plants, microorganisms and animals through the process of biosynthesis or derivatives from primary metabolites. The maceration method is a simple way to separate bioactive compounds from plant material. Guava leaves contain secondary metabolite compounds which have medicinal effects such as antibacterial, antioxidant and anti-inflammatory. This simplicia leaf is soaked in 96% ethanol (using the maceration method) for 24 hours and concentrated using a rotary evaporator. Alkaloid, flavonoid and saponin tests show that guava leaves contain these three compounds. These compounds have potential for development in the pharmaceutical field.

The increasing use of plastic materials in daily life has led to a rise in plastic waste, contributing significantly to environmental pollution. This study aims to analyze the characteristics of insects that contribute to the eco-friendly degradation of plastic waste and to evaluate the rate of plastic waste degradation and the waste reduction index (WRI) achieved through insect larvae. The research uses a Randomized Factorial Design, investigating plastics such as styrofoam blocks, low-density polyethylene, polyurethane, polystyrene, and a control. The parameters examined include insect characteristics, larval length and weight, degradation rate, and WRI. Both Zophobas atratus and Tenebrio molitor exhibit the potential for the bioconversion of plastic waste. The weight of T. molitor larvae ranges from 0.07-0.09g, while Z. atratus larvae weigh between 0.51 and 0.60g. The WRI is directly proportional to the reduction rate, with higher reduction rates corresponding to higher WRI values. The results showed that the control using Z. atratus and T. molitor larvae achieved the highest WRI values among all treatments. Among the plastic types studied, styrofoam blocks showed the highest WRI value, indicating that a feeding rate of 1g of plastic per larva per day is optimal for efficiently reducing plastic waste. This supports circular economy initiatives for companies developing insect-based proteins for food, feed, and natural products while advancing sustainable development goals.

Cyanobacteria play an important role in the evolution of the earth and biosphere. Cyanobacteria play a role in the oxygenation of the atmosphere and oceans that began since the great oxidation event. These living things are the main producers in the ocean in the past and present and are the ancestors of Chloroplasts. The morphology commonly used is still difficult to read for microfossil interpretation which makes the identification of cyanobacteria in the early fossil record still ambiguous. This study was conducted to review classical and new cyanobacterial biosignatures. In addition, this study will also analyze the fossil record of cyanobacteria mentioned earlier and the challenges of molecular approaches to modern cyanobacteria. The suggestions we provide are new calibration points for molecular clocks and strategies to increase insight into the timing and patterns of cyanobacteria evolution and oxygenic photosynthesis.