Methanotrophy is a biological process that effectively reduces global methane emissions by utilizing microorganisms that can utilize methane as a source of energy under both oxic and anoxic conditions, using a variety of different electron acceptors. Methanotrophic microbes, which utilize methane as their primary source of carbon and energy, are microorganisms found in various environments, such as soil, sediments, freshwater, and marine ecosystems. These microbes play a significant role in the global carbon cycle by consuming methane, a potent greenhouse gas, and converting it into carbon dioxide, which is less harmful. However, methane is known to be the primary contributor to ozone formation and is considered a major greenhouse gas. Methane alone contributes to 30% of global warming; its emissions increased by over 32% over the last three decades and thus affect humans, animals, and vegetation adversely. There are different sources of methane emissions, like agricultural activities, wastewater management, landfills, coal mining, wetlands, and certain industrial processes. In view of the adverse effects of methane, urgent measures are required to reduce emissions. Methanotrophs have attracted attention as multifunctional bacteria with potential applications in biological methane mitigation and environmental bioremediation. Methanotrophs utilize methane as a carbon and energy source and play significant roles in biogeochemical cycles by oxidizing methane, which is coupled to the reduction of various electron acceptors. Methanotrophy, a natural process that converts methane into carbon dioxide, presents a promising solution to mitigate global methane emissions and reduce their impact on climate change. Nonetheless, additional research is necessary to enhance and expand these approaches for extensive use. In this review, we summarize the key sources of methane, mitigation strategies, microbial aspects, and the application of methanotrophs in global methane sinks with increasing anthropogenic methane emissions.

In limited growing conditions, intercropped field peas and oats can represent a significant source of forage rich in protein. If applied correctly, factors such as nitrogen fertilizer, the mowing phase, and sowing norms can significantly increase the productivity of these mixtures. Field trials were conducted to examine their productivity under different nitrogen levels (0, 40, 80 kg ha⁻¹), different sowing norms/mixtures (field peas: oats—100:15%; 100:30%), and two stages of growth (full flowering, full pod formation). Nitrogen fertilizer and different sowing norms had a significant effect on the biomass, hay, and crude protein yields. On average, the highest hay yields were achieved with 80 kg ha⁻¹ N (4.96 t ha⁻¹), followed by 40 kg ha⁻¹ N (4.27 t ha⁻¹). The highest protein yields were achieved with 40 kg ha⁻¹ N (CP—704.1 kg ha⁻¹), followed by 80 kg ha⁻¹ N (CP—637.6 kg ha⁻¹). Sowing norm 100:30% achieved higher hay yields: 100:30%—4.82 t ha⁻¹; 100:15%—4.44 t ha⁻¹, while 100:15% achieved higher crude protein yields: 100:15%—730.4 kg ha⁻¹; 100:30%—692.7 kg ha⁻¹ on average. The costs were not significantly increased with the nitrogen fertilizer, but the net profits were increased by as much as 163%, depending on the nitrogen level and the mixture. Nitrogen fertilizer also achieves higher economic efficiency for the mixture 100:15% compared to the 100:30% mixture. Mixtures of field peas and oats outperform single-grown crops and provide cost-effective feed for a short time. Using optimal seed ratios and nitrogen fertilizer can significantly increase the productivity and profitability of the feed with minimal impact on the overall production costs.

The identification of wheat genotypes with balanced grain yield, stability, and antioxidant response to abiotic stress is crucial for creating adaptable varieties in changing climates. The research was conducted as a multi-environment trial (MET) across six environments (three localities over two seasons), and included 15 wheat genotypes (bread wheat lines, standard varieties and two spelt wheat lines). This study integrates AMMI and GGE biplot analyses with antioxidant profiling across growth stages to identify genotypes combining yield stability and stress tolerance. Lines KG-4/1, KG-11/1 and the variety Pobeda were identified as high-yielding and stable genotypes, with KG-11/1 ranked as an “ideal genotype” and KG-4/1 achieving the highest grain yield on MET level (6.48 t ha^–1). Specific adaptation of genotypes KG-40/1 and Renesansa indicates their potential for targeted breeding in particular environments. Antioxidant parameters (TPC and DPPH• scavenging activity) at early growth stages were positively correlated with grain yield, indicating that they can serve as suitable biochemical markers for selecting stress-tolerant, high-yielding wheat genotypes. This comprehensive approach, which includes the analysis of grain yield stability/adaptability and antioxidant parameters, is adequate for the evaluation of promising lines that may be suitable genetic resources in climate-resilient wheat breeding programs.

Perennial ryegrass represents the most important forage grass, yet its generally low drought tolerance leads to reduced yields under water scarcity. Nevertheless, large intra- and inter-population variability could be a pool for selecting new drought-tolerant varieties. In this study we evaluated three populations (K-11, Exp population and Shandon) under semi-controlled conditions across four watering levels (100%, 70%, 50% and 30% of field water capacity), focusing on yield and key morphological and biochemical traits. Dry matter yield and root dry mass decreased in all populations under limited watering conditions. The highest biomass production in such conditions was observed in the Exp population, likely due to better root performance in the deeper soil layer. On the other hand, oxidative stress markers (MDA and H₂O₂) and water-soluble sugars, which indicated the best physiological status in cultivar K-11 under severe drought, did not lead to the highest DMY. These results show the importance of including multiple physiological and biochemical traits in breeding processes, with the aim of developing perennial ryegrass cultivars capable of withstanding prolonged and intense summer drought as a consequence of climate change.

Milijana BABIĆ, Debasis MITRA, Pradeep K. DAS MOHAPATRA, Olivera PAPOVIĆ, Jasmina MILENKOVIĆ, Goran JEVTIĆ, Snežana BABIĆ & Snežana ANDJELKOVIĆ - ENVIRONMENTAL ASSESSMENT OF SOME HEAVY METALS IN SELECTED MEDICINAL PLANT SPECIES ALONG A BUSY ROAD IN VRNJAČKA BANJA, SERBIA, Carpathian Journal of Earth and Environmental Sciences August 2022, Vol. 17, No. 2, p. 259 – 265; DOI:10.26471/cjees/2022/017/219