Bertrand, Gabriel

(b. Paris, France, 17 May 1867; d. Paris, 20 June 1962)

biochemistry.

Gabriel Bertrand introduced into biochemistry both the term “oxidase” and the concept of trace elements. The son of a Paris merchant, Bertrand early showed an interest in the natural sciences, especially in the botanical specimens in the collections of the Muséum d’Histoire Naturelle. After obtaining his baccalaureate degree in 1886, he entered the École de Pharmacie in Paris, at the same time enrolling in Edmond Frémy’s courses at the chemical laboratory of the museum.

In 1890 Bertrand was appointed préparateur to Albert Arnauld, who had just taken over the course in organic chemistry after the death of his teacher Michel Chevreul; Bertrand held this post for ten years. He had also been noticed by Émile Duclaux, Pasteur’s successor at the Institut Pasteur, and in 1900 was appointed to the staff of the recently created institute of biochemistry at the Institute.

Duclaux was professor of biochemistry in the Faculté des Sciences, Paris, although his teaching was done at the lnstitut Pasteur. After Duclaux’s death in 1904, Bertrand was placed in charge of his courses; in 1908, he was named to the vacant chair, a position he held until his retirement in 1937. But retirement for Bertrand did not mean the end of work, and for many years thereafter he remained a familiar sight at the Institute.

Bertrand obtained his doctorate in 1904 with a dissertation that was a study of the conversion of sorbitol (D-sorbitol) into sorbose (L-sarbose), a sugar first identified in the sorb berry. He found ultimately that the conversion depended on the presence of a microbe, Bacterium xylinum (i.e., Aerobacter xylinum), and that it was an oxidation occurring only in the presence of oxygen. In the years 1894–1897 Bertrand investigated the process of the darkening and hardening of the latex of lacquer trees. He recognized that the color change was caused by the oxidation of a phenol—laccol—in the presence of another substance, laccase. Other phenolic compounds, he found, underwent similar organic oxidation reactions, also in the presence of substances similar to laccase. In 1896 Bertrand first used the term “oxidase” for these oxidizing enzymes (including tyrosinase, which he had described). During the following year he published several studies of oxidases.

Bertrand made another important advance in the analysis of enzymes when he observed that laccase ash contained a large proportion of manganese. Throughout the last half of the nineteenth century it had been known that plants contained minerals, and in 1860 it was demonstrated that in artificial situations plants could be grown in a water culture containing only metallic salts. Researchers still accepted the presence of minerals in the plant as incidental, however, and thought them the result of the presence of minerals in the soil. Bertrand’s work in 1897, and especially his later claim that a lack of manganese caused an interruption of growth, forced a change in thinking on this matter. He concluded that the metal formed an essential part of the enzyme, and, more generally, that a metal might be a necessary functioning part of the oxidative enzyme. From this and similar researches he developed his concept of the trace element, essential for proper metabolism.

During his career Bertrand published hundreds of papers on the organic effects of various metals. In 1911 he showed that the development of the mold Aspergillis niger was greatly influenced by the presence of minute amounts of manganese. For such researches Bertrand was forced to develop more precise methods of organic analysis, many of which later came into widespread use.

Bertrand’s researches were immediately applied to the elimination of previously undiagnosable pathological conditions, thereafter recognized as the result of deficiencies of trace elements. His work also provided the basis for further elaboration of the enzymatic systems involved in respiration and metabolic processes.

BIBLIOGRAPHY

I. Original Works. Among Bertrand’s articles are “Sur le latex de l’arbre à laque,” in Comptes rendus de l’Académie des sciences (Paris), 118 (1894), 1215–1218, which also appeared in Bulletin de la Société chimique de France, 11 (1894), 717–721; “Sur le latex de l’abre à laque et sur une nouvelle diastase contenue dans ce latex,” in Comptesrendus de la Société biologique (Paris), 46 (1894), 478–480; “Sur la présence simultanée de la laccase et de la tyrosinase dans le sue de quelques champignons,” in Comptes rendusde l’Académie des sciences (Paris), 123 (1896), 463–465; “Sur une nouvelle oxydase, ou ferment soluble oxidant, d’origine végétale,” in Comptes rendus de l’Académie des sciences (Paris), 122 (1896), 1215–1217, which also appeared in Bulletin du Muséum d’historie naturelle (Paris), 2 (1896), 206–208, and in Bulletin de la Société chimique (Paris), 15 (1896), 793–797; “Nouvelles recherches sur les ferments oxidants ou oxidases,” in Annales agronomique, 23 (1897), 385–399; “Les oxidases ou ferments solubles oxidants,” in Revue scientifique, 4th ser., 8 (1897), 65–73; “Recherches sur la laccase, nouveau ferment soluble, à propriétés oxydantes,” in Annales de chimie, 12 (1897), 115–140; “Sur l’emploi favorable du manganése comme engrais,” in Comptes rendus de l’Académie des sciences (Paris), 141 (1905), 1255–1257.

With M. Javiller, Bertrand wrote “Influence du managnésesur le devéloppement de l’Aspergillis niger, “Influence combinée du zinc et du managèse sur le développement de l’Aspergillis niger,” and “Influence du zinc et du manganése sur la composition minérale de l’Aspergillis niger,” all of which appeared in Comptes rendus de l’Académie des sciences (Paris), 152 (1911), 225–228, 900–902, and 1337–1340 , respectively.

II. Secondary Literature, Two biographical memoirs appeared soon after Bertrand’s death, one by Y. Raoul in Bulletin de la Société de chimie biologique, 44 (1962), 1051–1055, and the other by Marcel Delépine in Comptes rendus de l’Académie des sciences (Paris), 255 (1962), 217–222. The former was to be reprinted separately as a pamphlet containing a complete bibliography of Bertrand’s works, but has not yet appeared. No other complete bibliographical listings are available, although partial listings may be found in the Royal Society Catalogue of Scientific Papers, XIII, and in Poggendorff, V and VI. Bertrand’s relationship with the Institut Pasteur is discussed in Albert Delaunay, L’Institut Pasteur. Des origines à aujourd’hui (Paris, 1962).

The presence of metallic salts in plants was demonstrated in the nineteenth century, as was their ability to maintain plant life. See W. Knop, “Ueber die Ernährung der Pflanzen durch wässerige Lösungen bei Ausschluss des Bodens,” in Landwirtschaftliche Versuchsstationen, 2 (1860), 65–99, 270–293; and J. Sachs, “Ueber die Erziehung von Landpflanzen in Wasser,” in Botanisches Zentralblatt, 18 (1860), 113–117.

Alan S. Kay