May is Asian American and Pacific Islander Heritage Month—a wonderful time to highlight the many pivotal social, cultural, and scientific contributions of the people who have Asian and/or Pacific Islander lineage in the U.S. This year, we’re highlighting Fan Qingsheng, a dynamic scientist who accomplished a great deal in the realms of botany, antibiotic production, microbial pathogenesis, and public health efforts to thwart infectious diseases in both the U.S. and China. While the benefits Qingsheng imparted to these fields were all significant, his work was especially pioneering in the study of nitrogen availability in soil and the bacteria that positively contribute to it—helping the U.S. (and the world) make huge strides in the science of crop development.
Beneficial Bacteria: Living Their Best Lives
Healthy soil is a key ingredient for farming success and nutritious crop production. Fertile soils harbor a plethora of beneficial bacteria, constituting a unique ecosystem that aids in soil-water dispersal, nutrient cycling, and plant-disease suppression. In our everyday lives, we typically are taught to avoid bacteria in order to sidestep foodborne illness. But in the case of soil, there are many vital “good guy” bacteria that help plants and ecosystems thrive. In fact, the United States Department of Agriculture (USDA) has noted that a teaspoon of productive soil generally contains between 100 million and one billion bacteria!
Bacteria display varied activity in soil and are grouped into four categories: decomposers (which convert plant matter into forms of food for other living organisms in the soil); mutualists (which become partners with plants and convert atmospheric nitrogen (N2) into nitrogen for plants); pathogens (which can cause disease in plants but can also facilitate helpful antibiotic production in soil); and lithotrophs and chemoautotrophs (which obtain energy from compounds of nitrogen, sulfur, iron, or hydrogen instead of from plants or other organic matter). Nitrogen (which composes about 78 percent of the air we breathe) is a particularly essential nutrient for the soil that helps plants grow and is naturally found in the atmosphere. Yet not all the nitrogen in the air or soil can be used by plants: Only two to three percent of nitrogen in the soil is found in a form that is usable by plants (inorganic nitrogen).
Mutually Beneficial, for Bacteria and for Us: The Work of Dr. Fan Qingsheng
Our current knowledge of beneficial agricultural microbes and nitrogen availability can’t be fully discussed without mentioning Dr. Fan Qingsheng. Qingsheng was a botanist by training, first making a name for himself by developing the first herbarium in China in the 1930s. In 1940 he migrated to the U.S. to obtain a master’s degree from the University of Wisconsin-Madison, where he went on to earn his doctorate while researching the physiology of photosynthesis in the alga Chlorella pyrenoidosa. Qingsheng’s doctoral work spurred a deeper interest in studying microbiology and antibiotic biochemistry, specifically that of penicillin (one of the most popularly used antibiotics globally), while also continuing to support research that explored the potential symbiotic relationship between plants and beneficial microbes associated with agriculture.
During World War II, still living in the U.S. but aware that widely available penicillin could help China’s soaring infectious disease rates, Qingsheng pursued an opportunity in 1943 to return to China to aid the American Bureau for Medical Advancement in China (ABMAC), helping establish China’s first blood bank in Kunming and working as a diagnostic bacteriologist there. He also began working for the Chinese Center for Disease Control and Prevention (China CDC) to develop penicillin reserves for Chinese citizens. With Qingsheng’s collaboration and insights, the China CDC successfully produced its first batch of penicillin, making China the seventh country capable of producing this critical, life-saving antibiotic.
Later, in the 1970s, Dr. Qingsheng did expansive research in China on the plant Astragalus sinicus, bringing to light its diverse usage in the field of agricultural productivity. Among its benefits, A. sinicus can fix nitrogen, enrich soil fertility, act as animal feed, serve as a source of pollen for bees, and be used as an anti-inflammatory herbal supplement. In 1978, Qingsheng’s research on A. sinicus won him the First Chinese Science Congress’s First Prize. Throughout the 1980s and 1990s, Dr. Qingsheng continued his work on microbes by focusing on the development of antibiotics to control agricultural pests and pathogens and investigating the biological nitrogen fixation of soil microbes. Alongside his over 60 years of teaching, Dr. Qingsheng’s contributions to numerous scientific projects and research initiatives promoted the idea “that a healthy soil microbial community containing various beneficial microbes could help plants defend against infectious diseases and agricultural pests” and maintained that these same insights could be incorporated into animal husbandry and fishery management.
The contributions of Dr. Qingsheng to global agricultural, biological, and medical science are striking and enlightening—and he is just one of the many people of Asian descent to impact the U.S. food and public health systems in unquantifiable ways. You can learn more about AAPI Heritage Month here and more about Asian Pacific American history here. Happy AAPI Heritage Month—may this year’s celebration include education, gratitude, and respect for the lives and contributions of people with AAPI heritage!