Many soil microorganisms have important uses in industrial production processes, and many more uses and organisms will probably be discovered as bio-prospecters, taxonomists and genetic engineers continue to attempt unravel the immense taxonomic, functional and genetic diversity of microbes (Nisbet and Fox, 1991). For example, the University of Florida recently patented a strain of fungus identified by Brazilian farmers as being lethal to fire ants and a Uruguayan bio-control nematode for use on golf courses (RAFI, 1995). The University of Massachusetts has patented a bacteria from Costa Rican soil that shows useful anti-fungal and nematicidal properties and Mitsubishi has patented and marketed a streptomycin-based antibiotic isolated from Argentine soil that will be used in poultry and swine feeds (RAFI, 1995).

Some microorganisms are already being exploited as direct producers of food for human or animal consumption. For example, mushroom ‘hunting’ plays an important role in several societies both as a leisure activity and for economic purposes. Some mushrooms such as the truffles are real (and expensive) delicacies. Nevertheless, the vast majority of modern human societies, particularly urban, do not recognize the immense diversity and potential benefits of soil biota. It is difficult for even well-trained, experimented taxonomists to memorize the names of a few thousand species, let alone that society in general remember the names of 600-18,000 invertebrate species living in mixed or natural landscapes (Paoletti, 1999). However, herein again, lie the benefit of discovering and using bio-indicators, and of educating the society as to the role of soil ‘critters’ in natural and agro-ecosystems, industry and other human activities.

Case study. Indigenous use of soil organisms as a direct nutritional source (Paoletti et al., 2000, 2003)

A recent survey conducted by Paoletti (1999) demonstrated the extremely poor knowledge of biodiversity of western civilized persons (in this case students of Padova University, Italy), compared with that of native Amerindians from Venezuela (Table 1). An assessment of the estimated number of species of food consumed by each culture revealed that the students knew a total of only 75 edible species of plants and animals, while the Amerindians could identify from 108 up to 390 species. Of these, no insects were consumed by the students while up to 61 species were consumed by the Yanomamo. In fact, some indigenous groups even manage the population of their invertebrate foods by deliberately introducing them into new habitats; Paoletti (1999), for example, observed how the Makiritare Indians (Alto Orinoco River, Venezuela) disseminated their favoured edible earthworms into beaches of the Orinoco’s affluents.

At least 32 Amerindian groups in the Amazon basin use terrestrial invertebrates as food. Leaf- and litter- consuming invertebrates provide the more important, underestimated food sources for many Amerindian groups. Earthworms are an important component of the diet, as described previously by Wallace more than one century ago (1853). By consuming these litter-feeding invertebrates Amerindians of the Ye'Kuana group recover proteins, fat and vitamins. This offers a new perspective for the development of sustainable animal food production within the paradigm of biodiversity maintenance, highlighting the urgent need to raise awareness among the different sectors of the society as to the importance of soil biological processes, biodiversity, and soil biota at various levels of the human existence.

Table 1. Estimate of the number of species of plants and animals eaten by traditional cultures (Amerindians) and “modern” western civilises persons (Italian students from Padova University) (Paoletti, 1999).

*Includes other terrestrial invertebrates such a earthworms

**Includes marine and freshwater invertebrates

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