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Microorganisms discovered with the rise of Rio Grande are the basis of life and may be of metal origin

Publicado em 26 maio 2021

Researchers conducted the first large-scale study of the microbial fauna present in the Ferromanganese crust of the seamount and described the bacteria and archaea involved in the nutrient cycle and metal formation.

The abundant biological and mineral diversity of Rio Grande Rise, a seamount at a depth of the Atlantic Ocean about 1,500 km from the Brazilian coast, is probably due to little-known microscopic creatures.

Researchers at the University of São Paulo Institute of Oceanography (IO-USP) have collaborated with colleagues at the National Center for Oceanography in the United Kingdom to investigate microorganisms inhabiting seamount ferromanganese crusts, with bacteria and archaea probably He concluded that he was responsible for maintaining the livelihood of a prosperous area. In addition to being involved in the biomineralization process that forms the metals present in the crust.

Articles published in the journal Microbial ecology Describes research funded by FAPESP and the Natural Environment Research Council (NERC) in the United Kingdom.

In 2014, the International Seabed Authority (ISA) awarded Brazil a 15-year grant for mineral development rights to Rio Grande Rise. The ISA, consisting of 167 Member States and the European Union, is required to organize, regulate and control all mineral-related activities in the international undersea region under the United Nations Convention on the Law of the Sea. This is about 50% of the total. World waters.

“Little is known about the biodiversity of the region and the impact of mining on ecosystems,” said Vivian Pellizari, a professor at IO-USP and a senior researcher.

This study was part of a thematic project supported by FAPESP. This article is one of the results of a PhD study by Natascha Menezes Bergo, a postdoctoral research intern at IO-USP.

“The process known as microbial biomineralization is well known, but the oxidation and precipitation of manganese has not been proven and it was not known how it occurred in the marine region. In May, an article by a US researcher Nature For the first time, we have shown that bacteria use manganese to convert carbon dioxide into biomass through a process called chemosynthesis, “said Bergo, who participated in sampling in 2018 on the British research vessel RRS. I will. Discovery..

“One of these bacteria belonging to the phylum Nitrospirae DNA A sequence extracted from a crustal sample collected at Rio Grande Rise. This is strong evidence that the metals there are formed not only by geological processes, but also by biological processes in which microorganisms play an important role, “she says.

In addition to iron and manganese, the crust is rich in elements such as cobalt, nickel, molybdenum, niobium, platinum, titanium and tellurium. For example, cobalt is essential for the production of secondary batteries and tellurium is an important input for the production of high efficiency solar cells. In late 2018, Brazil applied to the ISA for a continental shelf expansion, including Rio Grande Rise.

In other parts of the world, similar areas that have been studied for the same purpose for a longer period of time include the Clarion-Clipperton Zone and Takuyo-Daigo Seamounts in the North Pacific Ocean, and the Tropical Seamounts in the North Atlantic Ocean.


The area of ??Rio Grande Rise is approximately 150,000 km. 2 It is three times as large as Rio de Janeiro and has a depth of 800 to 3,000 m. The rise formed when present-day Africa and South America separated from the supercontinent Gondwana between 146 million years ago (mya) and 100 mya is about 40 mya, probably due to the weight of the volcano and its lava. It was an island that sank. The movement of the structural plate.

During one of the 2018 expeditions, researchers collected ferromanganese crust and its inhabiting coral skeleton, as well as calcarenite rocks and biofilms on the surface of the crust, from some of Rise’s samples. These biofilms are structured microbial communities wrapped in substances that are secreted to protect themselves from threats such as nutrient deficiencies and potential toxins.

“Finding biofilms was an interesting surprise because it is an indicator of the early biomineralization process,” says Bergo. “We found the same microbes in biofilm, coral, calcarenite, and crust samples. The only difference was the age of the surface. Corals are newer than the crust and biofilms are younger.”

A total of 666,782 DNA sequences were recovered from the sample. Bacteria and archaea discovered by scientists belong to a group known to be involved in the nitrogen cycle, where ammonia is converted to nitrites and nitrates, and thus serve as an energy source for other microorganisms. To do. In addition to the phylum Nitrospirae, they have discovered other prokaryotes such as the archaeal class Nitrososphaeria. The sequence of samples also revealed groups involved in the methane cycle, such as Methylomirabilales and Deltaproteobacteria.

The results amplify scientists’ understanding of the microbial diversity and potential ecological processes found in the Ferromanganese crust on the South Atlantic Ocean floor. They also contribute to the future regulation of possible mining activities in the Rio Grande Rise region.

“When the crust is removed, it probably changes the local circulation, which changes the supply of available organic matter and nutrients, thus changing the local microbiome and all life associated with it,” Bergo said. Stated. “Moreover, the crust grows an average of 1 mm every million years, so there is no time for re-colonization. Many studies have recently been published on how to assess and mitigate the effects of deep-sea mining. Is not a coincidence. “

Reference: “Southwest Atlantic Ocean, Rio Grande Rise” by Natasha Menezes Bergo, Amanda Gonzalves Bendia, Juliana Correa Neiva Ferreira, Bramley J. Merton, Frederico Pereira Brandini, Vivian Helena Perizari Microbial diversity in the deep-sea ferromanganese crustal field, 16 January 2021 Microbial ecology..

DOI: 10.1007 / s00248-020-01670-y Microorganisms discovered with the rise of Rio Grande are the basis of life and may be of metal origin