TY - JOUR
T1 - Feed additives for methane mitigation
T2 - Recommendations for identification and selection of bioactive compounds to develop antimethanogenic feed additives
AU - Durmic, Zoey
AU - Duin, Evert C.
AU - Bannink, André
AU - Belanche, Alejandro
AU - Carbone, Vincenzo
AU - Carro, M. Dolores
AU - Crüsemann, Max
AU - Fievez, Veerle
AU - Garcia, Florencia
AU - Hristov, Alex
AU - Joch, Miroslav
AU - Martinez-Fernandez, Gonzalo
AU - Muetzel, Stefan
AU - Ungerfeld, Emilio M.
AU - Wang, Min
AU - Yáñez-Ruiz, David R.
PY - 2025/1
Y1 - 2025/1
N2 - Despite the increasing interest in developing antimethanogenic additives to reduce enteric methane (CH4) emissions and the extensive research conducted over the last decades, the global livestock industry has a very limited number of antimethanogenic feed additives (AMFA) available that can deliver substantial reduction, and they have generally not reached the market yet. This work provides technical recommendations and guidelines for conducting tests intended to screen the potential to reduce, directly or indirectly, enteric CH4 of compounds before they can be further assessed in in vivo conditions. The steps involved in this work cover the discovery, isolation, and identification of compounds capable of affecting CH4 production by rumen microbes, followed by in vitro laboratory testing of potential candidates. The finding of new bioactive compounds as AMFA can be based on 2 approaches: empirical and mechanistic. The empirical approach involves obtaining and screening compounds present in databases and repositories that potentially possess the desired effect but have not yet been tested, screening natural sources of secondary compounds such as plants, fungi, and algae for their antimethanogenic effects, or examining compounds with antimethanogenic effect on microbes in other research domains outside the rumen. In contrast, the mechanistic approach is the theoretical process of discovery new bioactive compounds based on existing knowledge of a biological target or process. The in vitro methodologies reviewed include examining effects at the subcellular level, in single pure cultures of methanogens and examining in more complex mixed rumen microbial populations. Simple in vitro methodologies (subcellular assessments and batch culture) allow testing a large number of compounds, whereas more complex systems simulating the rumen microbial ecosystem can test a limited number of candidates but provide better insight about the antimethanogenic efficacy. This work collated the main advantages, limitations, and technical recommendations associated with each step and methodology use during the identification and screening of AMFA candidates.
AB - Despite the increasing interest in developing antimethanogenic additives to reduce enteric methane (CH4) emissions and the extensive research conducted over the last decades, the global livestock industry has a very limited number of antimethanogenic feed additives (AMFA) available that can deliver substantial reduction, and they have generally not reached the market yet. This work provides technical recommendations and guidelines for conducting tests intended to screen the potential to reduce, directly or indirectly, enteric CH4 of compounds before they can be further assessed in in vivo conditions. The steps involved in this work cover the discovery, isolation, and identification of compounds capable of affecting CH4 production by rumen microbes, followed by in vitro laboratory testing of potential candidates. The finding of new bioactive compounds as AMFA can be based on 2 approaches: empirical and mechanistic. The empirical approach involves obtaining and screening compounds present in databases and repositories that potentially possess the desired effect but have not yet been tested, screening natural sources of secondary compounds such as plants, fungi, and algae for their antimethanogenic effects, or examining compounds with antimethanogenic effect on microbes in other research domains outside the rumen. In contrast, the mechanistic approach is the theoretical process of discovery new bioactive compounds based on existing knowledge of a biological target or process. The in vitro methodologies reviewed include examining effects at the subcellular level, in single pure cultures of methanogens and examining in more complex mixed rumen microbial populations. Simple in vitro methodologies (subcellular assessments and batch culture) allow testing a large number of compounds, whereas more complex systems simulating the rumen microbial ecosystem can test a limited number of candidates but provide better insight about the antimethanogenic efficacy. This work collated the main advantages, limitations, and technical recommendations associated with each step and methodology use during the identification and screening of AMFA candidates.
KW - docking
KW - in silico
KW - in vitro
KW - methane
KW - rumen
UR - http://www.scopus.com/inward/record.url?scp=85212868382&partnerID=8YFLogxK
U2 - 10.3168/jds.2024-25045
DO - 10.3168/jds.2024-25045
M3 - Review article
C2 - 39725500
AN - SCOPUS:85212868382
SN - 0022-0302
VL - 108
SP - 302
EP - 321
JO - Journal of Dairy Science
JF - Journal of Dairy Science
IS - 1
ER -