In 2008, it was 41. In 2012, it grew to 140. Now, the number is 262. What is it? It’s the number of aromatic compounds that bacteria are known to synthesize. A new third-generation inventory of "terpene synthase" genes in bacteria has revealed widespread ability in simple microbes to manufacture complex organic compounds. Each chemical compound is backed by one or more genes that codes for an enzyme machine ("synthase") able to construct it.

Yuuki Yamada and a team of six colleagues in Tokyo published their latest findings in the Proceedings of the National Academy of Sciences, announcing, "Terpene synthases are widely distributed in bacteria."

What are terpenes? They are smelly organic compounds (the name is taken from turpentine), volatile molecules that organisms use for various functions. The distinctive odors in a forest and in the soil are largely due to these chemicals produced inside living cells. Most are made by plants and fungi, although termites, butterflies, and other insects manufacture terpenes, and some of the largest and most complex are made by animals. A 2007 paper in Nature Chemical Biology listed some of the functions of terpenes and wondered at how evolution created so many different organisms able to use them:

As the largest class of natural products, terpenes have a variety of roles in mediating antagonistic and beneficial interactions among organisms. They defend many species of plants, animals and microorganisms against predators, pathogens and competitors, and they are involved in conveying messages to conspecifics and mutualists regarding the presence of food, mates and enemies. Despite the diversity of terpenes known, it is striking how phylogenetically distant organisms have come to use similar structures for common purposes. New natural roles undoubtedly remain to be discovered for this large class of compounds, given that such a small percentage of terpenes has been investigated so far. (Emphasis added.)

Now, the Japanese team has expanded that "striking" fact to bacteria, pushing the origin of the technology for synthesizing hundreds of complex compounds down into the simplest of organisms: bacteria. What’s also astonishing is that bacteria produce some unique terpenes not known from higher organisms, such as plants and fungi.

The majority of the terpene hydrocarbons that we have identified by heterologous expression of bacterial terpene synthases in the engineered Streptomyces host is known compounds that have previously been isolated from fungal, plant, or in some cases, bacterial sources. Significantly, however, we have also isolated and determined the structures of 13 previously unidentified cyclic terpenes, none of which have previously been described from fungal, plant, or bacterial sources (Fig. 3). Three such presumptive terpene synthases (SCLAV_p0765, SCLAV_p1169, and SCLAV_1407) from the terpene nonproducing organism S. clavuligerus turn out to have unique catalytic activities. Thus, the diterpene alcohol hydropyrenol as well as the diterpene hydrocarbons hydropyrene and isoelisabethatriene B were all isolated from the standard heterologous Streptomyces host carrying the sclav_p0765 gene. The former two metabolites are unique tetracyclic diterpenes with a parent skeleton that has not previously been reported in the same or modified form, whereas isoelisabethatriene B is a previously undescribed isomer of the known sea plume metabolite isoelisabethatriene. In like manner, none of the diterpene hydrocarbons clavulatrienes A and B, prenyl-?-elemene, and prenylgermacrene B, all of which are produced by a heterologous Streptomyces host carrying sclav_p1169, have been previously described, whereas the cometabolite lobophytumin C has previously been reported only as a soft coral metabolite….

The three diterpene hydrocarbons (tsukubadiene and odyverdienes A and B) produced by heterologous Streptomyces hosts carrying stsu_20912 and nd90_0354, respectively, are each unique structures with parent diterpene skeletons that have not been found in any organism to date.

Some terpenes are complex hydrocarbons (molecules made of hydrogen and carbon), with rings and repeating functional units. Others have oxygen, alcohol groups, and phosphate groups. Some are precursors to steroids, sensory molecules like retinol, or signaling molecules. Some 50,000 terpenes have been identified so far.

Many terpenes are very useful for humans. They are implicated in desirable ingredients in spices, beneficial drugs, vitamins, antibiotics, resins, rubbers, oils, fragrances, and cleaners, but they can also be dangerous, like those in hallucinogenic drugs and dangerous toxins. Smell an organism and you’re probably sniffing a terpene: the distinctive smells of orange, citronella, and mint are examples. Thank terpenes for the lovely smell of a pine forest or a rose garden.

Though some terpenes are variations on a theme (multiples of the C5 molecule isoprene), many are unique. Terpenes are complex organic molecules; some have as many as 40 carbons and complex 3-dimensional shapes. How difficult would it be for a sophisticated chemistry laboratory to manufacture 262 different kinds of terpenes?

There are industries devoted to terpene manufacture. Suppliers often simply extract the compounds from natural sources. Wikipedia says that "Many terpenes are derived commercially from conifer resins," for instance. To construct some of these molecules de novo is challenging. That’s evident from a 2010 Nature Chemistry paper about a new method for mimicking one natural terpene. Notice the last three words:

The plant-derived sesquiterpene englerin A is a potent inhibitor of several renal cancer cell lines. Two recent total syntheses have utilized cationic gold(I)-complexes to coax readily available open-chain precursors into englerin’s challenging oxotricyclic core with enzyme-like precision.

That is telling. The chemists were proud of themselves for getting their synthesis past a challenging step with the precision and ease of what a plant enzyme does every day.

And here’s the kicker: hundreds of these molecules are made by bacteria! That means they didn’t show up later in evolutionary time by some "innovation," but were there at the beginning, in prokaryotes. Each terpene presupposes a gene and an enzyme capable of synthesizing it: a specific synthase protein that had been coded for in the gene, then built in the ribosome. The terpene, the enzyme, and the gene are all connected in this process.

What’s more, the synthases appear in many different lineages of bacteria (though not in Archaea so far). The paper states:

Not unexpectedly, the predicted terpene synthases were mainly found in Actinomycetales microorganisms, reflecting presumably the significant numbers of Actinomycetales genome sequences in the current public genome databases. Additional predicted terpene synthases were also found in gram-negative bacteria belonging to the orders Myxococcales, Oscillatoriales, Nostocales, Burkholderiales, Herpetosiphonales, Rhizobiales, Chlamydiales, Flavobacteriales, Chromatiales, Ktedonobacterales, Sphingobacteriales, and Pseudomonadales.

Perhaps some of the synthase genes were shared via lateral gene transfer; that is not indicated. But the authors expected from their first two studies that the synthase families would fall into neat and tidy groups. However, in this latest study, the reality hit:

By contrast, the phylogenetic tree derived from the newly identified 262 bacterial terpene synthases uncovered by the third generation HMM model is considerably more complex, exhibiting a much higher degree of branching, thus indicating that bacterial terpene synthases are far more structurally diverse than previously indicated.

Indeed, their phylogenetic diagram makes unique branches look like the rule, and families the exception. The biological function of most of these terpenes remains to be determined. Now that we know that bacteria make many different kinds of terpenes, the authors of the PNAS paper believe that bacteria "represent a fertile source for discovery of new natural products."

It’s hard to overemphasize the challenge this presents to Darwinists. So many unique, functional chemistry labs in the simplest of cells! Each synthase enzyme knows how to make one of these complex molecules, and the organism knows how to use it. We can expect that many more will be discovered with ongoing research, like Nature Chemical Biology said: "New natural roles undoubtedly remain to be discovered for this large class of compounds, given that such a small percentage of terpenes has been investigated so far." Getting just one gene of any function is challenging for unguided natural processes, but 262 — in bacteria?

Remember, getting one functional protein by chance is prohibitively improbable. The combined public and in-house databases of bacterial genome sequences, they state, yield the following number of predicted proteins in bacteria — are you ready? It’s 8,759,463 proteins.