MINERÍA la mejor puerta de acceso al sector minero MINERÍA / SEPTIEMBRE 2023 / EDICIÓN 552 102 Presentación y discusión de resultados La diversidad es una propiedad emergente de las comunidades biológicas que se relaciona con la variedad dentro de ellas. Este atributo es la expresión de dos componentes: el número de especies presentes en la comunidad, riqueza, y la equidad, que describe cómo se distribuye la abundancia de los individuos entre las distintas especies que integran la comunidad (Tuomisto, 2012). En un contexto como este, de análisis de amplicones o metabarcoding, dichos índices se estiman a partir de la tabla de ZOTU limpia y filtrada. En la Tabla 2 se muestran los resultados del análisis de biodiversidad utilizando varios índices de diversidad alfa. Los dos primeros conceptualizan el término de riqueza, estos índices fueron la riqueza observada (S) o número total de ZOTU contabilizados y un índice basado en la riqueza estimada, Chao-1, en concreto, de media se estimó la riqueza en 72 (DE 140) ZOTU y en 72 (DE 140) ZOTU para Chao-1. La muestra con una mayor riqueza, superior claramente al resto, fue SNC1-2 con 531 ZOTU, las segunda y tercera muestras con mayor riqueza fueron: AC2-1 con 95 ZOTU y SC1-1 con 75 ZOTU. Las muestras con menor riqueza observada fueron SC2-1, SC3-1 y ANC1-1 con 10, 10 y 14 ZOTU, respectivamente. El resto de los índices representan la diversidad en la muestra, para estos se obtuvieron los siguientes valores medios para el conjunto de las muestras: índice de Shannon (H) fue de 2.70 (DE 1.00); para el índice PD, que además tiene en cuenta las distancias filogenéticas entre ZOTU, fue de 12.36 (DE 11.95); finalFigura 4. Abundancia relativa observada (%) de las clases de procariotas. Cada barra vertical representa una muestra (N=13). Se presentan las clases más abundantes en todas las muestras y los taxones con una abundancia global inferior al 1% fueron colapsados en una sola categoría nombrada como “Otros” (en gris). Figure 4. Observed relative abundance (%) of prokaryote classes. Each vertical bar represents one sample (N = 13). The most abundant classes in all samples are shown and taxa with an overall abundance of less than 1% were collapsed into a single category named "Other" (in gray). 2021), which is a Helix BioS in-house development. This double filtering of taxonomic data allowed to obtain the best possible taxonomic resolution. Next, two data cleaning steps were performed. The first step was to exclude from the analyses both ZOTU whose sequences belonged to chloroplasts or mitochondria, in order to keep those sequences genuinely prokaryotic and those ZOTU not identified at the phylum level. And the second step consisted of filtering in an unspecific way all those ZOTU whose total abundance was less than or equal to 25 reads in the set of samples, thus reducing the technical noise generated by the sequencing artifacts. From the set of filtered ZOTU, subsequent analyses of microbiological diversity and composition were performed (Garris et al., 2016; Hugerth & Andersson, 2017). For the description-analysis of the biodiversity and microbial composition of samples, the statistical software R v3.6.2 (R Core Team, 2019) and the libraries vegan 2.57 (Dixon, 2003), phyloseq 1.30.0 (McMurdie & Holmes, 2013)were used, while the DESeq2 1.26 library was used for the analysis of bioindicators(Love et al., 2014). The following alpha diversity indices were calculated with the samples: Richness (S), Chao1 Index (Chao1), ShannonWiener Index (H), Phylogenetic Diversity Index (PD), Inverse Simpson's Index (1/D). An important aspect in the analysis of the microbiota is the study of the microbial composition, i.e., which taxa and how often they are present in the samples. For this purpose, we worked with two types of abundances: the absolute observed abundance or count (n) and the relative observed abundance or proportion (%). Presentation and discussion of results Diversity is an emergent property of biological communities that relates to the variety within them. This attribute is the expression of two components: the number of species present in the community, richness, and equity, which describes how the abundance of individuals is distributed among the different species that make up the community (Tuomisto, 2012). In such a context of amplicon or metabarcoding analysis, these indices are estimated from the cleaned and filtered table of ZOTU. Table 2 shows the results of the biodiversity analysis using various alpha diversity indices. The first two indices conceptualize the term richness, these indices were observed richness (S) or total number of ZOTU counted and an index based on estimated richness, Chao-1, specifically, on average richness was estimated at 72 (SD 140) ZOTU and at 72 (SD 140) ZOTU for Chao1. The sample with the highest richness, clearly superior to the rest, was SNC1-2 with 531 ZOTU, the second and third richest samples were: AC2-1 with 95 ZOTU and SC1-1 with 75 ZOTU. The samples with the lowest observed richness were SC2-1, SC3-1 and ANC1-1 with
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