Moldy Marijuana, The Straight Dope
from High Times
Growers taking time to harvest a healthy cornucpoia of cannabis must also carefully watch over their cut crops. In addition to two-legged thieves, myriad bacteria, molds and insects have been known to rip-off your stash while curing, drying, or in the fridge. Avoiding these ubiquitous threats is nearly impossible, but there is a way to lessen their impact. The key is being able to manipulate storage conditions.
A variety of bacteria grow on damp marijuana. Many are deadly. Researchers have found _Klebsiella pneumoniae_, _Enterobacter cloacae_ and _Streptococcus_ (group D) growing in government-supplied reefer. _Salmonella muenchen_ was found in marijuana growing across the Midwest. (Let someone else roll the joints. I don't lick rolling papers anymore!) Under anaerobic conditions (i.e., damp marijuana stored in airtight containers), _Clostridium_ species will rot pot; these are the famous boutlism bacteria.
In addition, a number of bacteria-like Actinomycetes have been identified in confiscated ganja, including _Thermoactinomyces candidus_, _T. vulgaris_, and _Micropolyspora faeni._ These bugs cause allergic reactions (sometimes severe), as well as "Farmer's lung" disease.
Insects in pot are less intense. Growroom critters, such as aphids and spider mites, rarely damage marijuana after harvest. Smith & Olson (a list of references appears at the end of this article) identified five beetle species from confiscated Mexican weed in San Francisco. They completed this study at the request of the DEA agents, whose offices were overrun by the pests. The predominant species, _Tribolium confusum_ (confused flour beetle), attacks only seeds, not marijuana proper. Two other beetles cited in the study, _Adistermia watsoni_ and _Microgramme arga_, are fungus feeders (the marijuana was moldy). Thankfully, the researchers found no cannabis equivalent to _Lasioderma serricone_, the tobacco cigarette beetle. Otherwise some whacked government lab would be growing the bugs en masse to spread across the continent.
Fungi destroy more bud than bacteria and insects combined. Bacteria in marijuana may be more dangerous to humans, but they are rare. Molds are common, and can be nasty: Ramirez reports four policeman developing pulmonary histoplasmosis after pulling up a 5,000-square-meter plot of marijuana in Puerto Rico. Some fungi won't rot pot, but they will put you in the hospital.
Many fungi causing disease in plants die off after their host is harvested. Exceptions include _Botrytis cinerea_ (the cause of gray mold) and _Alternaria alternata_ (brown blight). After harvest, your competition becomes _Aspergillus_, _Penicillium_, _Rhizopus_, and _Mucor_, the baddest actors on the planet. Each genus causes disease under different conditions:
Ubiquitous _Aspergillus_ grows on anything from rocket fuel to astronauts. The genus is millions of years old; while _Home sapiens_ may come and go, _Aspergillus_ will remain. Westendorp first found an _Aspergillus_ species attacking _Cannabis_ in 1854. More recently, Margolis & Clorfene describe a mold that _increases_ potency in marijuana. Their "black weblike fungus" sounds like an _Aspergillus_ species. _What_ species, I'd like to know....
Schwartz scraped _Aspergillus niger_ from the skull of a marijuana smoker experiencing sinus headaches. I frequently encounter _A. niger_ growing in ganja stored at room temperature. It does _not_ increase potency. Kagen also reports _A. niger_ growing in moldy marijuana, along with two _even nastier_ Aspergilli: _A. fumigatus_ and _A. flavus._
Chusid et al. blame _A. fumigatus_ for causing near-fatal pneumonitis in a 17-year-old. They note the patient buried his marijuana underground for "aging." No doubt the patient was looking for Margolis & Clorfene's fungus, but _A. fumigatus_ found him instead. _A. flavus_, on the other hand, kills slowly. It oozes carcinogenic metabolites called aflatoxins. Llewellyn & O'Rear found aflatoxins contaminating Virginian marijuana.
_Aspergillus_ species grow better in warmer climates, _Penicillium_ in cooler climates. Refrigerator storage encourages _Penicillium_ infestation. Kagen et al. isolated _Penicillium_ from marijuana cigarettes. Babu et al. identified _P. chrysogenum_ attacking marijuana. (_P. chrysogenum_ occurs abundantly in nature, and was Alexander Fleming's source of penicillin.) I isolated _P. italicum_ from marijuana stored with an orange peel at 0 degrees Centigrade. Adding peels to pot imparts a "pleasant bouquet" (Frank & Rosenthal). In my case, the peel imparted a nidus of infection. _P italicum_, the "blue citrus mold," is notorious for its ability to spread by contact (i.e., "one bad apple spoils the whole bunch").
Five _Mucor_ species have been described on _Cannabis._ Members of this genus grow fast and die young. One of them, _M. hiemalis_, regrettably bioconcentrates (and cannot metabolize) the herbicide paraquat from tainted substrates (Domsch et al.). _Mucor's_ first cousin, _Rhizopus,_ occurs in soil, ripe foodstuffs, and occasionally on people (especially diabetics). Grebeniuk isolated _R. stolonifer_ from hemp stems. In an inoculation experiment, I quickly rotted some damp marijuana with a colony of _R. stolonifer_ found growing on bread.
DIAGNOSIS Rotting marijuana produces a spectrum of odors, from stale to musty to moldy. _P. italicum_ perfumes a lavender bouquet, while _A. flavus_ smells like a locker room. _Clostridium_ bacteria stink like carrion.