Increased production of reactive oxygen species or ROS is one of the common responses to a wide range of biotic and abiotic stresses. Increased production of ROS is outstripping endogenous

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magna as feed has advantages: easy to digest, the size is in accordance with the larval mouth opening, has 42.65% protein in the form of nutrition, contains a number of digestive enzymes, does not degrade water quality and can be cultivated in bulk. In this study, commercial catfish pellets fermented with probiotics were used as feed for D. magna. The probiotic that is often used in aquaculture is EM4 (Effective Microorganism 4). EM4 is able to play a role in increasing protein levels and with the right dose, EM4 becomes the main determining factor in growth productivity. The purpose of this study was to determine the good duration of EM4 fermentation in population growth of D. magna. This study is an experimental study (CRD), using D. magna as a test animal, with 5 different treatments. The results of the density of D. magna which were given different treatments gave different results. The highest density was found in treatment 3 and the treatment that had the lowest density was in treatment 5. The results of the Nonparametric test (Friedman-Test) showed significant results (P=0.00<0.05). Significantly different treatments were in treatment 3 and 5, while treatment 2 and treatment 4 had no significant difference. The results of the study the highest specific growth rate obtained was in treatment 4 of 0.223%/day, then followed by treatment 3 of 0.211%/day, while other treatments were relatively lower. Thus, feeding in the form of catfish pellets fermented with EM4 on the population growth of Daphnia magna gave a significant effect on treatment 3 and treatment 5 with the highest specific growth rate in treatment 4.

Plants growing in soil containing heavy metal polutan such as chromium (Cr), lead (Pb), cadmium (Cd) and copper (Cu) will be stunted, and increase production of Reactive Oxygen Species (ROS). In dealing with the excess amount of ROS, plants have an enzymatic defense system, using superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxide (APX). The aim of this study was to determine and analyze the Sonchus oleraceus (Linnaeus, 1753) plant response to heavy metals stress, seen from the growth and antioxidative defense enzymatically. Research carried out using a Completely Randomized Design (CRD) with four treatments and five replicates. The metal treatment was 10 mg ⋅ L −1 . The presence of heavy metals in the growing medium significantly decreased the plant height and leaf area, so the impact is on the weight of wet and dry weight. The metal treatments of Cr, Cd, Pb and Cu increase the activity of SOD and APX enzymes but decrease the activity of the CAT enzyme. Chromium is a metal that has a significant influence on the growth and activity of SOD, APX, and CAT enzymes in S. oleraceus.